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Discussion Starter · #1 · (Edited)
The old girl arrived safe and sound have been spending the past couple of days getting acquainted with it in the garage. I finally fired it up and took it for my first ride today. If you'd like to get a firsthand experience of what it's like, then you can read my review below after the pics.

The Basics
When you first throw a leg over it you realize how light it is. Really light. If you're used to riding two strokes and the weight wasn't so noticeable, the hard and unforgiving seat instead will catch your attention. It is probably partly this way due to its age. The gas tank is large and sits up high in front of you, but is unusually quite narrow and slim on the sides like an MX bike. Flick the kick stand up and you wonder if you almost broke it because it feels very light by the way it went up. You definitely feel like you're on something that's retro by the lines of the tank and style of the plastics, but the ergonomics are not so far vintage that you feel like you're on something from the early 70's.

You work the controls a bit to get a acquainted with their positions. The bar is nice and flat (it's actually an aftermarket bar) with a very comfortable reach that doesn't feel anything out of the ordinary. The Magura throttle system is quite heavy in feel with strong return spring pressure. Magazine editors back in the day had complains that it and the front brake lever required too much muscle to operate and could cause fatigue after a while. The clutch lever on the other hand (literally) is light. You then attempt to work the rear brake but you find that your boot rolls off the peg instead as if the brake lever isn't even there. What? The rear brake lever is somewhat oddly mounted inboard with the bike so you have to actually position your boot up and to the left in order to fully activate it smoothly. It's not mounted directly in front of the peg like most bikes so you realize you better work it several times to become comfortable with its orientation.

Starting it
This is where it gets fun. Kicking this thing over is downright scary; plain and simple. The good news is that it does seem to want to start (some bikes just plain don't and will fight you until the end) but it seems to actually be working on your side to do so which is good. You can either use your left leg, unnaturally, to do it while on the tall seat, or, kick it with your right leg standing off the bike while trying to keep it from coming off the kickstand at the same time. Whatever nonconformist style you chose produces a low and fierce sounding "glug glug" as you turn it over that growls through the exhaust like the echoes the clown in the movie "IT" makes in the sewer pipes. Stories you read of folks having their calves shattered in half or legs broken quickly dance in your mind. You ask yourself "what if" and question if the risk is worth the reward. You press on the lever about 1/4 of the revolution down just until it goes over compression. The feeling is like the kick starter all of a sudden engages what feels like a stuck rock that simply won't budge any further. I use the analogy of a rock because that's exactly what it feels like once the lever comes into compression. When you kick over a big 4 stroke and you reach compression stroke, it will still often feel somewhat "rubbery" with a tiny bit of give at that point. This... notta. Nothing. Zilch. The motor might as well be locked up solid. Even when you put your entire body weight onto the lever it still will not even budge a millimeter or give you any indication that it will. At this point you say a prayer, and jump on it as if your life depended on it with the hope that the lever doesn't spring back up with enough force that could land you on the moon. If your best Hulk impression still did not move the lever one or both of two things will have happened; you either put a nice gouge in the tread of your boot and/or the bike almost fell over.

If you think bump starting this thing is a second option, think again. I initially tried this but unless you are a heavy weight, it wants lock up the tire when you let the clutch out... even in 5th gear.

If you were successful with the kicker, the lever will have gone half way down its revolution and your ears all of a sudden begin bleeding with a very rewarding joy. I felt like I had just won a gold in the national Olympics when I fired it for the first time. The sound of it is VERY loud. POP POP POP, BANG BANG BANG, CRACKLE CRACKLE CRACKLE. You almost need ear protection standing next to it when it idles it is that loud.

What is it like to ride?
To be honest, I had naively been wondering just how "powerful" it was going to feel next to modern day machines and thus preparing myself that it may not exactly what I had been envisioning. I was just going to enjoy for what it is. Boy, could I have ever been more wrong.

I don't think I could ever post enough of those "yikes" smilies to justify this bike. It is hands down the SCARIEST bike I have EVER ridden in my entire life. I used to review motorcycles for a part time job and have ridden varieties from all over the spectrum. Forget 1000cc+ liter bikes. The acceleration this thing has is pure insanity to the tenth degree. Violent. Pure i-n-s-a-n-i-t-y. I was shaking after my first ride on it as if I had just gotten out of a cold shower. I have not even gotten past a 1/4 throttle yet as the bike just wants to explode out from under you. I'd describe it like a stick of dynamite. Again, pure insanity. Insanity! You almost ride the clutch on this thing more than you're on the throttle. As you give it a hair of throttle input it takes off like you're going down a roller coaster. Basically if you give it any throttle it says "oh, you want a piece of me?" You let off the throttle but then you don't slow down at all because it has hardly any engine braking. You reach for the brakes and while the front works, you totally miss the rear because of the akward positioning that you still haven't mastered yet. You've got a lot other things on your mind at the moment so you can forgive yourself for that.

As you're riding, you quickly begin to notice the heat from the expansion chamber on the left side begin getting hot so you have to swing your leg out to not burn yourself. It's hot, there's no heat shield, and it's easy to bump your leg on it which I seemed to repeatedly do. Eventually I'll get the picture. Surprisingly it is smooth in the low end, then as the revs build the vibes begin to come. Unlike some of the other 500 open classers of the time, this one came with a heavy flywheel which helps mask vibrations.

I go back to the noise because it is a lot louder than I expected it to be. The exhaust has a factory spark arrestor so it's not like it's running an open pipe either. I was even a little concerned this thing might sound a little too plugged up and already considering options of having a custom muffler made. Turns out you need ear plugs to ride it as the "BANG BANG BANG" makes you think there's bottle rockets going off inside your helmet. When it idles it's nearly as loud as a 4 stroke single that is running straight out of the manifold with no exhaust system. It's ridiculous, every part of it!

It is by far the most absurd and scariest machine I have ever experienced in my life. I can only wonder what the heck would happen if you were to fully open the throttle. The bike would probably shoot out from under you doing multiple backwards somersaults until it eventually crashed into some trees in the next state. I now understand why these are called "widowmakers."

Now for the serious question... will I ever be able to start it again? ;)

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Discussion Starter · #4 ·
Thanks guys.

I took it out for another brief ride today on a gravel road and gave her a little more stick. People online have been encouraging me to give it full throttle to experience what it's like "on the pipe" but you'd need a good mile or two of open stretch to do anything like that. I did get into about 1/4 throttle and the rear tire just spun into the oblivion.... brrrRRRRRAAAAAPPPP!!!!

I drained the coolant and ordered some Evans Waterless Coolant which will prevent corrosion from happening inside the magnesium water pump. The guy Andre from Andre Horvath's Enduro Klassiker - André Horvath's - said that he should have the aluminum reproduction pump covers hopefully available mid 2016. Until then, the waterless coolant will at least stop any future corrosion.

I'm not sure how it would do riding in traffic if I ever were to make it street legal. It is kind of like riding something that's on nitrous and may all of a sudden just jump out at you at any given moment. I am nonetheless going to eventually install a headlight and brake light.

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Discussion Starter · #7 · (Edited)
Reminds me of riding my old Husky, at least you have disc brakes mine were drum. Yea, kick starting one of these old ones can be fun. Even with moto boots on, I've plowed my ankle into the ground more than once. And yes kick back can be a b----.You just sit there till you can feel your knee again. Ah the good old days. Have fun, be safe.
Those vintage Huskys are some of the neatest vintage looking bikes. Yeah, starting them is half the experience.

It's easy to see why the original owner may have gone MIA...

Austen NICE KTM!! and the Ducati!! I have not been on any large 2 stroke Liquid cooled dirt bike like that.. What do you think the HP is?? But I do like my 2 strokes!! I have snowmobiles with 700, 800, 900 cc 2 strokes 165HP. So I know what on the pipe means and it is a rush!! Just take it easy and you will get the feel of the bike. I am sure you have ridden many bikes and some are just an animal to ride and that is what make it feel so good to harness it. Ride safe!! AGAT (All Gear All Time) I guess I need to get my 75 Yamaha RD350 on the road..
Thanks! The seller included some factory literature and the specs list it as 62HP. KTM apparently also approved race fuel.

I'll bet your snow machines are an absolute blast!! Wow, I can only imagine how fast they are with that kind of HP. I'd love to experience one of those. You should start your own thread for them! :2th:

You've read my mind and you speak my language. There's something super rewarding about harnessing (as you state) an animal of a machine. It's what my two motorcycles have in common. There's never a dull moment.

Yup, this bike is one that you don't ride without gear. That is for sure.

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Discussion Starter · #9 · (Edited)

As my dad always says after you purchase a vehicle, "what is the assessment." In other words, what surprises good/bad have come to light that you weren't aware about during the purchase.

1. Do not under any circumstances flood it when you're attempting to start it. I flooded it really bad earlier this week and it became a nightmare to get running again. Once it's warmed up, it'll start with 1 or 2 dynamite kicks. Just DO NOT flood it when you are trying to start it when it's cold. I've been trying to find little tricks to getting it started more easily so I've been trying to start it at least once a day to become comfortable with it and try and develop a system. I've found that charging the cylinder by rocking the bike back and forth in 3rd gear few times, then shutting OFF the fuel usually has positive results. Tipping it over on its side floods if you're not careful. If you leave the fuel on and she doesn't light off in 2-3 kicks, you best call it a night or find shelter if you're stuck in the mountains.

2. I've discovered there is a slight exhaust leak in one of the seams in the expansion chamber at the very bottom. I first noticed it when I flooded it real bad and fuel began seeping out of it. Apparently Andre from Enduro Klassiker may be offering reproduction expansion chambers later this year so I may wait to just get a new one instead.

3. The reed cage boot has some cracking from age. I was a little surprised the owner I got it from didn't address this when he went through it. I was concerned so I tested the cracks by spraying them down with carburetor cleaner but noticed no difference in running which is good. Eventually it'll need to be replaced and I'll install a Boyesen reed cage that has an aluminum tract vs. a rubber boot that can dry rot like the original.

4. I drained the coolant and installed Evans Waterless.

5. I learned there was a recall in regards to the ignition on these. Apparently in some situations timing could advance when you were kicking it over and the engine could actually begin running in reverse because of it. If that happened, the kick starter would slap back up and usually break the starting mechanism at the same time. I'm not sure if the recall was done on this bike. So far there haven't been any serious kickbacks.

6. I came across a couple of additional MX magazine reviews of the bike and learned that it has 18:1 compression which is largely responsible of why it is so hard to kick over. Apparently KTM suggested that if you were having trouble starting yours, that you could install a thicker head gasket which lowered the compression ratio a little bit thus making it easier to kick over. I'll buy an electric starter roller before I ever go that route, though.

7. It is the scariest sounding machine. The "pop" (or rather "bang") from the exhaust when it idles is nearly the same decibel level I'd say as a 4 stroke when it back fires. Almost like a shotgun going off. You really do almost need ear protection just standing next to it as it sounds like constant backfires going off. The sound of the engine itself when you're riding it sounds plain scary. It is very "echoy" and has a haunting/deep tone to it.

8. The power, again, is almost uncontrollable and takes your mind into another dimension. You really can't roll into any throttle at all unless you have at least a mile ahead in front of you. It is crazy thing it is. If you roll into it and it doesn't find traction it'll just burn a hole in the earth but then out of nowhere it all of a sudden slings you forward with a sledgehammer like force. When it finds traction it may all of a sudden wheelie or the back end might jump out. If you were to take your mind off of riding the bike for at least a second, there is the potential that you could be thrown off and not wake up again until you're in the hospital. Riding it in tight areas takes an immense amount of concentration.

9. Fuel consumption. It goes through fuel as if you drilled a hole on the bottom of the tank and let it run out. One little ride and you've already blown through a gallon of gas.

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Discussion Starter · #13 ·
Yea, every machine has its problems and characteristics. 18:1 Makes my leg hurt thinking about that. I guess you should use race gas. At least Prem fuel for a easy ride.

I would like to here that pipe 'pop' as you say. I have been to enough races and other shows that have open pipes on 2 strokes. Some motors really have a nice sound. It just make me want to go look at the motor and find out more about it. Now how about a triple 800 2 stroke with megaphones!! That is just plane LOUD. A guy I know has one..
Premium for sure! I'll have to mix up some race fuel for it. The engine does not have a power valve either.

I'll bet the triple 800 sounds nice!

That thing scares me just reading about it.
It's a trip!

nice ktm austen, as a young teen with a hodaka wombat and riding a friends ossa 250 I wondered why anyone would want a larger two stroke dirt bike.
" I guess I need to get my 75 Yamaha RD350 on the road "
yes you do, I got a chance to ride one of these and while not dirt bike scary it made my cb 350 look bad, real bad
Thanks, I know what you mean there!

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7,335 Posts
Discussion Starter · #14 · (Edited)
Boy, I've caught this "vintage" open class 2 stroke bug hard. It's a totally different breed of bike that I've never owned or experienced before. I think back to riding bikes like modified CBR1000RRs that were complete monsters to ride on the street, 190HP Ducatis, and this is just a whole different level of scary excitement that no kind of bike can offer. I'd love to see it find a CR500 garage partner. I guess there was a reason why a lot of times the teams had to literally help the riders off their bike after race due to complete fatigue.

In proper gearhead fashion, a new set of motorized wheels doesn't remain in its current state as he bought it for long, whether that be dramatic or subtle, after the papers are signed.

There were a few "pressing things" that I wanted to do to get the bike fully ready before I really took it out this summer in the mountains. I've listed them below.

Boysen Rad Valve


The original reed cage was beginning to develop cracks in the rubber intake track. Boyesen fortunately offers one of their rad valves for this motor which has an aluminum track that eliminates the issue of cracking. Reason enough to justify the "need" over "want" for one of these. The Boysen Rad Valve is a dual stage reed valve system, a design Boyesen apparently discovered several decades ago. A stock single stage reed valve system works similar to a powerband in that it works most effectively at a certain RPM range. The dual stage design solves this by incorporating two different style valves with different tensions that react effectively at separate RPM ranges. The carbon reeds (low tension) are lighter and open in the lower rev range and as you increase the throttle, the larger and more heavier (high tension) fiberglass reeds (yellow portion in the photo) open up at higher RPMs. The design is supposed to offer better throttle response and smoother power delivery.

Additionally, the Rad Valve straightens out the angle of airflow from the carb to the reed valve which helps reduce turbulence by smoothing out the airflow which provides a more constant velocity. With the development of the mono-shock, the carburetor was now required to be offset to one side so it no longer had a straight airlow track from the carb to the reeds resulting in the air flow having to change directions.


After putting it back together, I was able to get it started on the second kick which was a pretty cool feeling. The carbon fiber reeds are definitely more responsive right off the bat. I could notice it when as soon as I twisted the throttle in neutral by how quickly it revved compared to before. These vintage big bore KTMs have a heavier flywheel and it seems to have made it respond a lot quicker as if it had a lighter weight flywheel. In terms of overall power, it seems the same. I guess the only other thing is that it may have smoothed out the powerband a little bit down low.

Airbox to carburetor boot


The PO who definitely performed a lot of good in bringing this bike back to life such as installing an upgraded Keihin carburetor also took a few shortcuts along the way I've discovered. An example of this is in the custom airbox- to-carburetor boot that had to be made to accept a CR500 Keihin carb. The problem was that he used an automotive tire inner tube which wasn't holding up well to the heat of the motor. I ended up replacing it with an automotive silicone hose reducer and trimmed it length. It should be a permanent solution.

The other notable shortcut was that he seemed to have a love affair with gasket maker instead of ordering the correct gaskets (many of which are still available) from a company overseas. I'm slowly addressing this as I go along.

New front tire & wheel bearings

The original front tire was dry rotted and needed to be replaced. While the wheel was off, I replaced the front wheel bearings as one of the outer was dry and becoming to fall apart. One thing always turns into another!


I wanted a way to track mileage without always having to stop and pull my phone out while on the trail. An odometer was an optional feature on these bikes but not already outfitted on this one. A period correct look is what I was after over the practicality of a modern computer like a Trailtech so I did a little research and happened to find a complete used take off odometer system from an '85 MXC500 on Ebay. The issue was that the meter itself read kilometers instead of miles so I ordered a new, OEM, meter that reads mileage instead. Again, I know this is a very old school system instead of running a small computer that has a lot more features but I wanted the period correct look and want to keep things really simple on this bike.

Also, I've decided for now anyway that I'm not going to make it street legal. I really like the vintage styling and don't like the idea of mucking it up with a headlight, taillight, probably signals, and having to run a computer system with wiring to run the electronics. I may feel differently in the future but I don't picture myself riding this psychopath on the street anytime soon.

An extra touch to the right side panel

Can you spot it?

I think I've mentioned before that a certain recall was performed to eliminate the issue of deadly 18:1 compression kick backs that would more importantly break the starting mech due to timing advancing too far on start up. When the timing advances too high, the engine tries to run in reverse and can if it starts. I've read of one case where this happened and the rider got a chest full of handlebar when the bike unexpectedly went in reverse when he tried to get the holeshot! Note to self; let the clutch out slowly after starting to confirm engine is running in the correct direction.

What's next?

Not too much. After said work I told myself it's just about done. I will have to replace the front number plate with a reproduction because the top mount can no longer be used with the odometer meter and more importantly, it's missing the top straps that wrap around the bar. Right now the top is just secured be a zip tie. I may replace all the plastic with reproduction and put a green number instead of blue like pictured below but we'll see. I'll have a new expansion chamber made sometime in the future.


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Discussion Starter · #19 · (Edited)
Austen, There is always a reason to put performance parts on. At least that is what I tell my wife. You are probally correct on the Boyesen rad reeds that they will give it more bottom end and smooth out the power band. A little more HP on top end never hurts either!! They need to make Boyesen reeds for our Lawn Boys.. More Power YEA !!
Haha, agreed! I like the idea of performance reeds for 2 cycle OPE. :idea:
JEEH Austen, your like me can't leave her alone! ;)
Nice upgrades and write up! I kinda know of some of this stuff now. I helped my friend Bob buy a old Polaris Scrambler 4x4 from a co worker. Was sitting in shop all apart for over ten years. Engine in box. Bob just got her running Friday! Two strokes sound so cool! I MIGHT take it for a ride!!
Nothing wrong some personalization. :2th:

Nice! Yeah, you definitely should take it for a spin. You might find yourself in the market! :ThumbUp:
I sure do enjoy your write ups. It's like being there, and I have to say, I'm not sure I'd get on that KTM a second time myself. I did chuckle a bit while reading about the Boyesen reeds. I had a set of dual stage carbon fiber Boyesen reeds on the Honda PA50II that I had tricked out a few years ago. They made such a noticeable change in it, yet I can't even imagine what yours have done for your KTM.
Thanks Bruce,

I guess I try and write them in a way so that I can vividly go back and remember each step of the project.

I'll bet the Boyesen reeds made a noticeable difference in your Honda! :2th: It's pretty neat and effective design. I'm surprised the dual stage setup isn't a standard setup with the OEMs today.

Wow, you're really going the extra mile to make it super special! I'm impressed by how clean the engine is in the closeups, but I suspect that won't last long.
It'll be detailed after rides. :2th:

This is kind of a cool documentary a 1980s open class 2 stroke bike dezert race that I think captures what these bikes are about.

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Discussion Starter · #22 · (Edited)
Those pipes! Those pipes!! Wow! :ThumbUp:
I'll bet that machine is a rush! I'm sure the sound of that triple is incredible. Thanks for the photo and detailed description! I have a sense of what it's like to ride. :cool I like that it's a none power valve motor too.

I'm sure you're going to love the Boyesen reeds. You'll have to report back once you get them installed.

Yes, those GT550s and H1s are cool bikes. Many have made them into drag racers.

I'm glad I found another such another diehard 2 stroke enthusiast!! They offer a totally, one of a kind, adrenaline pumping experience. I'm foaming drooling at the mouth just thinking about going for a ride! :sidelaugh
In regards to the race, yeah, I didn't understand what the cause was for the cracked cylinder. I also thought the part were the "dust was clogging up the muffler and slowing him down" was a little weird. I had never heard of the Finke race either.

Man, I'm hooked on these 2 stroke open class bikes!!! :ROFL I've got a CR500 planned for my future. I'd like to find a 1985-1986 CR500 and do a modern CRF450 upsidedown fork conversion along with rear shock and also convert the swing arm to accept a disc brake.

I could talk this stuff for hours. :sidelaugh :p


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Discussion Starter · #25 · (Edited)
Better get your popcorn out because this installment is two parts in one. The first part consists of a series of more updates to the bike and secondly my first real exploration into the mountains with it.

Recently I took it out on a maiden voyage on some local trails with a co-worker who also rides. It was a good shakedown test to see if there was anything that I wanted to change before I took it on a trip. After the ride, I noticed that a couple of seals had blown where Permatex had been used so I placed an order with "Enduro Klassiker" in Austria that specializes in parts for vintage bikes like this and got an assortment of new gaskets where suspected gasket maker.

1. A nice trickle of smoke was puffing out from where the expansion chamber meets the head and sure enough the gasket maker had failed and blown out. The design of how the expansion chamber attaches to flange is not very good. It made sound weird, but using stretch and seal plumbing tape is what other owners swear by to use to solve the issue so that is what I did. No more leak.

2. Secondly, and more disturbing, I noticed some very small droplets of coolant starting to ooze out from the head "gasket." After I removed the head I found quite a few droplets of coolant scattered inside the cylinder as you can see in the photo below. It must have been losing a fair amount of compression here combined with the air leak in the exhaust; I'm surprised that it ran as well as it did. It most likely was burning some white steam mixed in with the smoke of the exhaust that I didn't notice. In any case, it turns out the head gaskets for these are made out of some extremely thin material, it is basically thinner than a piece of copy paper. This is why I it was tough to identify what was or wasn't in there before other than Permatex. I actually broke the one I bought when I was installing it so I said "forget it" and made my own new head gasket out of some very slightly thicker gasket paper.

3. Something else I came across which I thought was noteworthy. When I ordered all my gaskets for a '1986 KTM 500' the water pump gasket in particular, which I indeed verified is for a 1986, does not fit. After looking at some microfiches I discovered the left side engine/clutch/water pump cover is on my bike is off a later 1988-1996 500/550. I had to re-order a later style gasket so that it would fit. At some point early on in the bike's life, I imagine, the cover was swapped out for a later style. The original may have suffered bad cavitation early on and had to be replaced. When I opened it up, I did find some cavitation inside the waterpump so I did what was recommended to me on the KTM forum and filled it with a coating of JB Weld. The Evans Coolant prevents corrosion but I didn't want to leave the existing cavitation exposed. Someday when replacement covers are available I'll replace it with an aluminum version.

4. While the bike was torn down for a while I decided to change the graphics to green as seen in the photos below. I also purchased new OEM style Acerbis plastics from Andre (Enduor Klassiker) as well. I'll store the original plastics with the blue decals in case I ever want to go back to them but for now I really like the green.

5. I also found a good used four pot rear brake caliper on Ebay from a later year KTM that will swap over. I plan to also install a more modern front master cylinder to provide increased braking power and will do that all at once sometime.

6. I also installed a new front fender brace support which was an option for these bikes originally. I think it adds another little bit of retro bling.

I had to modify the mounting a bit for it to fit.

7. During the same time period in the 80s, some of the smaller CC KTM dirt bikes came with these cool, stylish, magnesium ignition covers. I found one on Ebay and took my chances with it in terms of fitment, however, it seems to have disappeared in the garage!! I don't know where it went and still can't find it.... sooo odd to lose something like this. Anyway, when I actually did have it in my hands I discovered that it has a slightly different mounting bolt pattern than a 500's (of course) which is kind of a shame. It would actually mount if you were to flip it upside down however but that wouldn't look right. Really the only way that I can see to make it work would be to cut the center out of the original cover which would leave you with a mounting ring that you could then glue onto the mounting surface of this cover. Voila. I would also shave off the mounting tabs on this cover if I did go that route. Might give it a try in the future if I'm feeling ambitious. If you have any other ideas in terms of how it make it work before it's too late, let me know!


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Discussion Starter · #26 · (Edited)
2nd part, The Trip!

Let's see if it all paid off.

In this part I thought it would be fun to sort of document the trip in sort of an ADV Rider style. It gets a little annoying stopping all the time, taking off my backpack to get the camera out so I didn't take a zillion photos but you'll get the idea.

I realize most are not located on the west coast so this won't mean much, but the plan was to go riding where my dad and I have gone trail riding a lot back in the day near Lake Chelan. More specifically, over Cooper Mountain. It's about 4-1/2 hour drive from home. I was going to camp where we usually did too.

The plan was to drive to the camp site and stage there. It turns out our old super secretive camp site is now tent city. Definitely un-appealing in many regards. So, I decided I'd find another spot to camp while exploring on the bike so I staged temporarily elsewhere for the interim.

It didn't take long to realize that something had to be done to the tire pressure as traction was just not there, at all. This bike is like riding something that's on nitrous and has 1000HP underneath you. Giving it 1/4 throttle has the same effect as cracking the throttle wide open on a 'normal' bike only without having any lag, RPM build, up whatsoever. The power is just there instantly at any given point. I sound like a broken record here, but you really do almost ride this bike more off the gas than you do on the gas. Anytime you're on the gas you're basically in a full on drift, back tire squirling side-to-side while you're trying to counter steer the heck out of it. I ended up lowering the tire pressures down to single digits where the tires where almost spongy-balloon like; thank God for rim locks. It helped maybe 15-20%.

There were a few of these trails we used to ride that were now either overgrown or had a lot of downed trees. I had already crossed three smaller ones before I had gotten to this point and decided to turn around. The trail was increasinly getting narrower and narrower and I didn't feel like putting a ton of new pinstripes on the plastics and number plates.

This is more like it.

This is what I call the "burnt forest." It was quite an interesting sight. All of a sudden you just enter it. There was another person there taking photos too when I was passing through.


The 'look out. I had officially made it to Cooper mountain at this point. It was only 13 miles on the odometer but figured it'd be a good time to do a fuel check. I was almost dismayed to see that I was nearly at half a tank already! WHAT!?? If I had been on any of my former 4 stroke dual sports at I would have still had a full tank at this point.

I had a realization that because of the level of performance this thing pumps out, it's really not hard to understand why it goes through fuel so fast and I shouldn't complain about it either. You can't get both. This thing is not a dual sport, but that's not what I was hoping or wanting it to be either. I had kind of always thought it was my imagination when I'd notice a change in the fuel level after a short time running it a bit at home. I wasn't- it just goes through fuel that fast. These bikes came with an even small tank designed for MX tracks. This one has the large 3.1 but still has a limited range. I estimated it gets between 13-15 MPG.

I was feeling hungry and this seemed like a nice spot to stop. It is sure different that riding a four stroke going down hill because there's zero engine braking. I don't like coasting for long distances on 2 strokes without applying any throttle so it was a balance between using lots of brake input with little inputs of the throttle periodically at the same time.

Obligatory food pic.

Some pretty wildflowers.

Helmet hair! Helmet hair!! Nobody gets worse helmet hair then I do. If there was a product that lessened it, I would be the first in line.

Lake Chelan in the distance. The next goal was to find a new camping spot.

After some riding I decided to head down into Chelan to the "Lakeview Drive-in" to grab a burger for dinner. It was like spring break in Cancun, the beaches were filled college kids.

Nice view of Lake Chelan to eat your dinner.

Time to head back into the mountains to setup camp. I had found another, better, camp site that was more scenic than our usual. It was several miles further up a narrow and rough road where I had to go slow with the trailer.

The camp site.

Watched the sun go down.

And watched a movie before bed, haha.

I Didn't encounter any wildlife. There was a noisy owl that I heard at night and there was a wind that came through the trees that made a lot of noise. The spookiest part were three different cars that drove past at odd hours of the night. As my dad has always said, you sometimes have to watch out for the people you come across when you're out here vs. the wildlife.

The next morning I went for a short ride before I packed up and left. I found another trail I had never been on before and this one offered some long stretches that I could open it up a little.

Overall, a great trip! I have another one planned with my dad in Oregon in September. I'm sure in the meantime I'll post some more updates to the bike and maybe another ride report if I do another weekend trip with it.

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Discussion Starter · #28 · (Edited)
Awesome adventure!!! Those cars at all hours is not cool at all! Way world is today! You sleep in truck?
Yeah, spooky for sure. Most likely people looking for a camping spot but it's eerie when it's pitch black out and all of a sudden you hear a car and see their headlights slowly coming up the mountain road at 2:00 in the morning.

I slept in the bed of my truck. Had a blow-up mattress and a sleeping bag. I love looking up at the stars. :2th:

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Discussion Starter · #31 ·
Wow! Beautiful bike, beautiful scenery! What fun!

Glad ya got the motor issue sorted out. You wouldn't want a breakdown in the middle of nowhere. Today 06:24 PM

Yeah, that was the goal. With a bike like this you want to bring tools along just in case in your pack and I did have to use them a couple of times on the trail when a couple bolts came loose.

The second two cars might have been heavily armed DEA agents seeing what the first guy was up to in the middle of the night. ;)

Maybe it was Jesse and Walt!

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Discussion Starter · #33 · (Edited)

During my on-going research of 1980s KTMs, I discovered some of the < 500 displacement CC models (it may have only been the 250 model... I don't really know for sure) came with these really cool retro looking, magnesium, flywheel covers. "Digital Control"- These things are awesome!! From what I've seen, this same cover was not ever offered on the 500 which was treated to a much more plain/basic plastic flywheel cover in comparison pictured on the right above. Being a sucker for things like this, I had to at least try to see if I could somehow make one of these work on my bike.

I did some research and these covers seem to be typically listed in the $50-$85 range and saw some listed well over a hundred on some independent websites. I eventually came across this guy going cheap for $19.99 because it had some corrosion issues so I figured it would be the perfect one to experiment with and chop up. The question was how I was going to do it- more on that. When I initially got it in my hands, I discovered the bolt pattern was wrong for a 500.... of course.... (although it would've actually mounted upside-down) and the cable guide slots that you see molded in it are non-relevant to a 500 as well. The good news is that the cover is the right size to fit over the 500 flywheel.

After looking at both covers side by side, I devised a plan to make one cover out of both of them. This would be done by cutting off the non-relevant cable guide portion of the magnesium cover; the cut was made where you see the white line. The stock cover would then be trimmed off and then the two would be joined together via epoxy. This way I would still have the correct mounting plate/face of the original cover to mount to the bike but have the magnesium cover (or cap now) for the front side.

The big question was how I was going to cut the magnesium cover in a professional (and safe) manner. Good luck taking it down to the local machine shop and paying them a quarter of your monthly earnings to make a single cut. I had remembered our good friend and member, Ellis, (tiretrx) who had helped me out with another project a few years ago. I hesitantly asked him if he'd be interested in taking this on fully expecting him to say "get lost!!" :Ugh: after I explained the good for nothing project to him but instead he said send it on over! I couldn't have done the project without him. One of the things that is so great about Ellis and his machining services is that he understands our hobby so he's willing to go the extra mile to help us out at realistic prices. I couldn't recommend him higher! Thank you again, Ellis!

Was it worth the effort?

You know, I didn't know how it was going to look after it was mounted on the bike. If it turned out looking like any one of my many failed arts & crafts projects when I was in grade school, then I had every intention for it to hit the trash and be replaced with a new plastic cover. The idea on paper was that it would sort of match the magnesium clutch cover on the other side. I think I'm happy with it, it's sort of a funny idea I guess. It would probably look more pronounced if it was repainted.

2. I purchased a new Dynoport "Big Barker" muffler from Rich Daly, the owner of Dynoport.

Out on my last ride in the mountains the brake rod ended up losing one of the mounting bolts which made it flip up and shoot a hole right through the fear fender locking the up the rear tire at the same time. I thought the motor locked up when it happened. As the rod shot up, it apparently also put a small dent in the rear end of the muffler which was unfortunate but it gave me an excuse to get a different one which I was tentatively planning. While I was out on the trail when this happened, I removed the rod from the bike and rode back to the truck using just the front brake and fortunately had a spare bolt and nut that was the right size so I could remount it and continue riding with both brakes. It proved to me the importance of bringing extra tools and hardware along for this bike.

Aside from the damaged rear fender (already replaced) and muffler, there was no further damage to the bike. The remaining bolt that had been on the brake rod at the time of the incident was tight and had a nylon lock nut on it but I'm guessing the one that worked its way out did not. In any case, I replaced the mounting hardware on both ends with new locking hardware as I don't want that happening again but will still be keeping an eye on them.

Surprisingly the new muffler really isn't any lighter than the stock one.

Made a new joint connection

The original muffler was not straight-through like this one so I was wondering just how much louder it was going to be. The tone itself didn't really seem to change but the "bang bang bang" is louder. It was loud before but now it hurts your ears standing next to it while it's idling.

3. Air filter fitment: Before my last trip, I did a visual check of the air filter and it looked nicely oiled and clean so I left it alone. I could tell that it was a dual stage aftermarket and not the original which I thought at the time was a bonus. After I got back from my last trip, I pulled the seat and it was dirty enough for a cleaning but as I was removing it I discovered that it sat against the air box too loosely. The problem was that the air filter was simply too big for this application. No matter how I tried, it just did not make a good seal even with filter grease. I wasn't thrilled when I found this out. I learned on a forum that Suzuki DRZ400 air filters will work as a replacement and I actually happened to have a stock DRZ air filter from when I had one of these bikes. I found the DRZ filter is indeed smaller than the aftermarket one so I put it on the bike and it is a much better fit and seals tight like it's supposed to.


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Discussion Starter · #36 · (Edited)
Okay, I'm kinda confused. You said the brake rod came off, but it looks like it's cable operated. Do you mean the lower strut rod that holds the caliper assembly in place?
That would be it, "brake rod" for lack of a better term.

Below is a line with an arrow showing the path that it took when it came loose and went through the rear fender. The caliper twisted all the way around the disc from it's normal position when it happened.

I kinda like the mag cover!
lol, thanks Nico.

I actually took it off today and broke the epoxy loose and reattached it. I saw in the pictures that the lettering was slightly off center so I reattached it so it's now straight. Sometimes it's not until you see things in pictures that you see things they way they actually are.

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Discussion Starter · #38 · (Edited)
Thanks Eric, I will. I'm pretty curious to see what it's putting out in terms of decibels now at idle so I'll turn the i-Phone decibel app on and get an estimate. I'm guessing it's gotta be around 100 decibels at idle.

Got the cap centered.... it was bugging the heck out of me seeing the lettering slightly off center in those photos.

Here's a couple of pics that Ellis sent me of the machining. Below is a quote from his as well.

This one was pretty to the magnesium cover. Chucked it up on the ID, added some coolant, and put a .160" wide parting tool to it at 350 rpm's. Cap dropped like an egg into the nest.

The plastic version was chucked on the ID, but due to the amount of flex the part had, it had to be done gently. Actually turned the RPM's up to 500 to go for a freer cut, but dialed the feed rate down to a couple thousandths for rev. When I got it almost through, I unchucked it and finished the parting by hand with a deburring tool.


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Discussion Starter · #39 ·
Here's a short video of it running, Eric.

I turned the i-Phone decibel app on, shot it at the bike got, and got a max reading of 96 and a peak of 95 decibels on each fire while idling. The engine is cold when I took this so it's a little more smoky than when it's warmed up. The distance of each pop you see out of the exhaust gives you an idea of the compression.


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Discussion Starter · #42 ·
Over the weekend I got her out and fired her up after sitting since early October. A few kicks and... BAM.! :ThumbUp: :ThumbUp: Also installed some new white hand guards.

Next up will be to have a new cone style expansion chamber custom made by Jon Easton from Jemco but not sure if that will be this year or not. I love this beast! Here's a short video of fooling around on it too.

I think the white look better than the blue ones that were on it before.


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Discussion Starter · #43 · (Edited)

This past weekend a friend and his wife and I took a trip over to Eastern, WA to go riding and camping. It was hot being close to 100 degrees but still fun. Once we got into the trees it cooled off some. The bike ran great aside from not having a strong idle at higher altitudes. It didn't do this so much before so I think it has to do with the open muffler I put on it and reduction of back pressure. I played with the carb settings a little when I got back home but may need to put a larger pilot jet in it if it does the same thing the next trip out. This was the first ride of the year with it.

Below are some pics from the trip and also a few updates I did over the winter to it. I'll start off with the updates and then work down to the trip pics as that seems the most logical.

The most prominent thing was the upgrade to a stronger front brake system. I installed a new 13MM Brembo front master cylinder and a new Venhill stainless front brake line. The stock front master cylinder was either a 10.5mm - 11mm I was told. The feel now at the lever is now rock hard and does not fade at all like the old one would do. I'm very happy with the difference.

As you might remember, I also purchased a used four pot rear caliper last year. I sent it out to a vintage motorcycle brake specialist to be rebuilt but he had trouble sourcing seals as their no longer made. He found a set that he could order that might work but they came in a kit that was quite pricey. He actually convinced me not to use the 4 pot rear caliper on a dirt bike. It's unique, but it's not desirable on a dirt bike he said. He explained that they don't even use these in professional racing because the larger size can attract more mud etc, get in the way of rocks, and just isn't practical. He said if the rear brake works fine (it does) to not go through the trouble so I've decided to leave it alone.

The bike sat for a few months over the winter without being started. When I pulled it out in the spring and turned on the fuel, the carb float bowl gasket leaked so pulled it off and replaced all the rubber seals in it. At the time, I took the opportunity to install new black vent hoses as well as the ones on it were hard and no longer very pliable.

Replaced the carb bowl screws for some allen head replacements. One thing I'll never understand is why many carb manufactures put butter soft phillips head screws on their float bowls. They torque them down from the factory and after a while they don't want to do anything less than round out like a hot knife going through butter.

Swapped my DRZ400 air filter out for a proper one made for the bike.

I've also been slowly replacing some of the old fasteners that were aged and a little unsightly in my opinion with new stainless hardware here and there.

She got dusty!
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