My Lawnmower Forum banner

1947 Jacobsen Lawn King

21084 Views 36 Replies 5 Participants Last post by  Austen
Thought I'd share my recent addition.

This is a 1947 Jacobsen Lawn King side wheel mower and I had been looking for one of these specifically to go along with my Lawn Queen. One day I am going to completely restore it like I did with my LK, but for now I am enjoying it in it's original state.

I found it listed on CS who infact was the original owner of mower. It hadn't been used in 30 years and was sitting in a basement. The reason he quit using it was because it got to be too much mower for him to handle. I can believe it!

When I first got it, it had the engine was slightly seized from sitting, but it didn't take much at all to unseize it. The carburetor and gas tank were clean, so nothing needed to be done there. It had spark, but a weak spark (and did start briefly) so I installed a Nova II electronic igntion conversion kit. It ran great for about ten minutes this way, but then it died and lost spark completely. I bought an NOS coil last year for these engines, so I put that in it and now she's back up and running excellent now that it has a nice hot spark.

I degreased and took a lot of the mower as it was pretty darn greasy and dusty. I also replaced the rear caster assembly with a different style one that allows for further cutting height and raises the handle bar up to a more comfortable position. I also like the fact that it has a pnuematic tire so it goes well with the other two.

Speaking of tires, I replaced both of the drive ones as well because one was not taking air and was beyond repair due to dry rought.

Anyway, I'm more than thrilled to finally have own one of these and thought I'd share a little about it. Here is a video of it in action. You will also want to switch the video to 480P for the best quality if it isn't already at that setting.

These first few photos were taken the day I brought her home.

The mower that got me started into Jacobsens
See less See more
1 - 20 of 37 Posts
Thanks for sharing the photos and the video with the members here Austen! :cool:

I bet there were not too many overweight guys running those mowers for a living given the clip that they move along in drive. :D
Saw this on display at a local show a few weeks ago:

I have some more pictures to get posted to my website from that show and an old car show in June. Another tractor show coming up his weekend.
See less See more
Saw this on display at a local show a few weeks ago:

I have some more pictures to get posted to my website from that show and an old car show in June. Another tractor show coming up his weekend.
That's neat, looks like somebody fixed it up!

Looking forward to seeing your pictures, sounds like fun.:)
Yea, the only spots on it were some sprinkles of rain. Looked just like new. Makes me wonder though what happened to the rest of it. I assume it was probably on a real mower.
I assume it was probably on a real mower.
Yeah, it was definitely off an old reel mower. You can tell by the silver mounting plate it's sitting on.

It always kind of makes me sad in a way when people pull the engine off and scrap the mower.
Well it seems I can't leave well enough alone, or atleaste I thought I was done working on the Lawn King for a while.

I have a habit of sometimes pondering up ideas on how to improve my machines to a even better state than they already are even if there is nothing wrong with them, whether that be tastefully modifying or simply just detailing them. While trying to fall a sleep one night few a weeks ago, I was picturing myself mowing with the LK and thinking about how it mows a little on the fast side, just common nature for vintage reel mowers though. I remembered when I installed a smaller crankshaft pulley on my Lawn Queen a couple summers ago and how that slowed it down a little bit, but the Lawn King has sprockets, not pulleys. So after I got home from work the next day, I pulled the covers off her to count the teeth on the crankshaft sprocket so that I could do some research to see what my options were of what's out there that may or may not work for this application.

An 8 tooth sprocket it was, so after doing some research I found what I needed, a 41B7 sprocket. Now I didn't want to lower the gearing so much that it would be really slow and only be practical for like small yards and such, no, I still wanted to keep the integrity of the mower the same because after all it is a Lawn King and was designed to cut several acres a day and I didn't want to diminsion the nature of that. The idea was for it to be a little slower so that making turns while mowing and whatnot were more manageable and also so that you would not need to walk quite so fast behind it. Going one tooth smaller on a counter or crankshaft sprocket is approximately equal to going up 2.5 teeth on the big sprocket, bigger than two but not quite three. After reading the specifications for the 41B7 sprocket, I knew that it would need to be bored out because it comes with just a 3/8" min plain bore, plus it would need to be tapered slightly and a keeway made as well so that made things a little more complicated. BTW, the smallest size sprocket out there that I could find for a #41 chain that could possibly work for this application was a 41B6 (6 tooth) sprocket made by the same manufacture, but the face of the sprocket would've been simply too small for it to be bored to the needed size. After I recieved it in the mail, it was obvious that it was not wide enough to be bored out to the same size as the stock sprocket. I contemplated on a few different possible ways that it could be modified to fit such cutting the bore off of it and having a new bore made and welded on and also machining off the sprocket on the stock bore and welding on the smaller tooth sprocket, but I quickly decided against modifying the original for obvious reasons.

So long story short I ended up having to contact just about as many companies out there that I could find that specialize in making sprockets because they actually ended up just referring me to other companies instead because the job was 'simply too small' or 'they don't work anything this small'. Apparently the economy is flourishing yet. After I contacted the referred companies, I was basically told the samething that I was told before. But as they say, if there is determination, there is a way. I eventually found a local machine shop that would actually look at it to see if they could modify the 7 tooth some how, but they said that to bore out the face of the sprocket to the amount needed, it would not work so well with the hardening of the teeth and is really hard to bore once you get close. Most of the time teeth on sprockets are flame hardened for longer life and because of that, it's really hard to bore when you get close to them and you also do not want to weld near the teeth either which could weaken them. Interesting things that I learned and didn't already know. I also looked into having a new sprocket simply made to replicate the original, only with less teeth but the quotes that I got to do this were outrageous because most shops had large a minimum order amount, for example like $1300! So a short while went by and I recieved an email from one of the companies that I contacted (Kiesler Machine out of Indiana) in regards to making a whole new sprocket and they said that they could duplicate the original per my request of # of teeth for around $50! That is duable and worth it to me. I chatted with the gentleman this morning who sent me the email about it and went over everything to confirm that they can do it via the pictures and measurements I sent, so I mailed the stock sprocket out today to have them duplicate a new one. I decided to have them just make a 6 tooth sprocket instead because I'm not really sure how a 7 tooth would effect the speed of the mower that much. I mean I'm sure it would be a little bit noticable, but I do know that the 6 tooth which would equate to going up 5.5 teeth on the big sprocket will make a noticable difference in speed and for $50, I'd rather just do that.

You may be wondering by now after all of this why I didn't just get a bigger sprocket for the other end and that is because of clearence, a bigger sprocket simply wouldn't have been able to clear with the chain attached between the front and rear sides of the mower body among other things, so that was out of the question. See how close it is already?

Both sprockets together.

Measuring the bore from the front of the original 8 tooth sprocket. Keep in mind this is the small end of the tapered bore.

As you can see it would hardly be enough clearence there for it to be bored out with the keyway made as well and not too mention since it would need to be tapered at the end, it was out of the question.

While I was at it and it somewhat apart, I thought I would make a new crankcase cap bearing gasket (yeah, gotta make the gaskets 'cause you're not gonna' find new ones for one of these) as it had been leaking pretty bad. The perfect time for it as the sprocket had to come off anyway to take the cover off to access the seal. There was a small remain of what seemed to be second circular gasket inside the cover itself that appeared to seal the outside of the bearing to the innerside of the cap, however it does not show one being there in my parts diagram for some reason, but I made a new one for the location anyway.

So anyway, I'll update you guys once I get the new sprocket back and make a little video of it in action and you can compare the difference in speed versus my other videos of it. I will also need to shorten the chain I'm figuring atleaste a couple of links or more for the new sprocket as well.

See less See more
Cool! Keep us posted Austen. :)
I call this update "A Sprocket Success!". Although there is a little bad news too (not sprocket related) when you get to the bottom.

After a long two and half weeks back in early February of waiting and wondering while the sprocket was sitting at the shop I mailed it to explained earier, they were not able to do it because they said it was not possible. The diameter of a 6 tooth sprocket is simply not big enough to be bored out to the needed size, so I was back to square one again for a little while because they didn't want to attempt modifying the 7 tooth so I needed to find somebody else to do the work. As I mentioned earlier, "if there is a will, there is a way."
If you're up for a little read about sprockets and how it was able to work, then continue onto the next paragraph.

An option that I had mentioned before which was also suggested by another member here was to machine the teeth off the original bore, cut off the bore of the new 7T sprocket, bore out it enough to fit and weld it on. I've kind of gone back and forth with that idea. If it was possible to do this (it would've been extremely close because the 7 tooth sprocket had just bairly enough center material on it to be bored that close), the chain would not have sat all the way on the sprocket since the teeth would be so close to the hub due to the large bore diameter which of course would cause the chain to skip. A notch on either side couldn't be made for the chain links to 'sit in' because there was very little material between the top of the bore and the keyway. After comparing measurements back and forth while trying to contemplate different ideas to get something to work, it finally occured to me that it might work if I installed the new 7 tooth sprocket backwards after it was bored out and cut to length. After taking some more measurements, it appeared that there would be just enough room for the sprocket to be bored out with a keyway made to fit over the tapered part of the crankshaft some of the way. My reasoning for having the sprocket on backwards was for two reasons; one this would allow the nut to hold it snug without it comming into contact with the chain as it would if it were on the front side and two, it would place the sprocket positioning in same location as stock for the chain to line up correctly. Pretty important! ;)
I contacted Ellis (tiretrx) who is a master machinist that was up for doing the modifications to the sprocket. Finally somebody willing to do the work! Anyway, man did he ever do a teriffic job and everything literally turned out perfect sucess as can be! 10/10 for sure!! He sure know's what he is doing to say the least and I would highly recommend him for doing any machine work. It couldn't have been better, just take a look that pictures below how to see how precise everything is and how it had to be made. Thanks again for doing the work and keeping an old girl like this alive.

As I normally do with my updates, below are some pictures with more descriptions of the work done.

Here it is modified. He even went as far as polishing it up!

1.4CM bore.

I did have to dremel a bit on the inside of the sprocket as well as a tiny bit on the taper of the bore, but I totally 100% expected to do this. Just did a little tiny bit at a time until it slide right on right where I needed it to be and fitsI like factory. I was originally assuming that I would need to make a goove on the taper on the crank via a dremel wheel for the chain links to go into on the frontside, but to my surprise the chain fits all the way on the sprocket and does not rub at all! Nice!

As you can see, there is clearence between the nut and chain as I kind of explained about earlier. I changed the postion originally a couple of times of where the sprocket needed to be cut after further contimplation and measurements, so bless his heart for putting up with that, lol. Since the picture was taken, I put a lockwasher in there.

Here's a picture of the new decal I was talking about. It looks alright I think. I put a couple layers of clear over it for added protection which also helps it adhere better. I will take some more pics of it later on once I get the covers and everything back on so you can really see it.

Now I'm going to have to actually start lubricating the chain. Before when it had the leaky gasket, it pretty much acted like an automatic chain oiler, lol.

So far the bad news, you ask. Well it hasn't been ran since Christmas since I took it a part it soon after. I knew that this shouldn't be a problem, but then again something in the back of mind has just been floating around with a wondering if it wouldn't. Well after I got it all back together and you can only imagine the anticipation to fire it up and see what it was like to mow, it wouldn't fire, even a little. It was getting plenty of fuel flow, so I checked for spark and seemed to have a decent jump. I cleaned the spark plug which was a no go. I even put a brand new plug in it and nope, wouldn't even fire a little so I *you didn't just read this* sprayed a little starter fluid into the carb and it sputtered to life a little finally, but something was definitely wrong. It was/is doing the exact samething as my '49 Lawn Queen did several years ago before I replaced the igntion system in it which is rev really high then low simultaneously, have absolutely no throttle control/response whatsoever and be very hard to keep running. Not too mention, rub pig rich. I did however engage the drive a little bit at the times I did have it running and it moved A LOT slower than it ever did before, so I can definitely tell a difference with the smaller sprocket, although part of it is definitely due to the fact that it's not running right.

As you already know if you've been following the updates, I replaced all the stock igntion components with a Nova II kit and an NOS Wico coil and had great success with this combo until now. I guess it was a mistake to use the NOS Wico coil I had. I think I'm just going to start from scractch and buy a new Tecumseh igntion coil like the my other Jac has in it which has been more reliable than ever and maybe even a whole new Nova kit to like what I said before, start from scratch. I'll order up the parts this week as I want to use it soon for spring mowing comming up soon. I swear, this thing just seems to lovvve having me work on it.
Keep you guys updated...
See less See more
Just ordered a new coil and igntion kit.

This time the kit is gonna be tucked up under the flywheel like it should be.;)
Sneaky. :D

Good job on sorting out the details to get it all to work! :cool:

Another one of those little ideas we have that seems simple enough to begin with then gets a wee bit more complicated to pull off. :D
Another one of those little ideas we have that seems simple enough to begin with then gets a wee bit more complicated to pull off. :D
Isn't that ever true!? I couldn't agree more. Usually when I get into little projects like this I always wonder what the 'snag' is going to be and most everytime, there always is one in some shape or form which causes the project to be bigger or more drug out. It's just like when you want to go change the spark plugs in your vehicle, there is always that last one which you swear is impossible to get to in which case you have to start removing bunch of thing just to get to it.


so you remember when I replaced that crankcase bearing gasket and mentioned something about there being an inner gasket and all? Well, there pretty much lied the problem, I could here a slight hiss (air leak) comming from around the crankcase bearing seal. Basically what was happening is that it wasn't sealing on the inside, so air was being drawed in right through into the crankcase and then into the flow of the intake passage which lead to it start revving up and down on it's own. A big air 'ol leak. I had to make a bigger round inner seal as well as a secondary round outter seal until I could finally get it to seal 100%. It's hard to explain without actually taking it apart and showing you firsthand. It was actually a lot of trial and error as I ended up having to make different size gaskets and try placing them in slightly different positions and spots until it finally sealed, so had I known this was going to happen in the beginning, I would have not taken it apart in the first place. I was pretty much convinced at first that it was spark related because my Lawn Queen had these same exact systems before and the cause of it was spark related and being that I have a hard time trusting Wico components on these machines, I thought that's what it was. Anyway, the important thing is that it's up and running again like it's supposed to.

So now you must be wondering what it mows or travels like compared to before. Here are the big three differences that I noticed the most:

1. Travels slower;more low end.
It does travel slower. The biggest noticable difference from all of this is that you can use it a lot more in the lower rpm's where it definitely moves slower. As I sort of mentioned in the video, it has a lot more low end now and lets you take slower steps, unlike before when the rpm's were really low, it would still be moving at almost a pace. Once you begin to give it some throttle though, it speeds up into what I call the 'middle stage' and is not a ton slower than it was before in comparison. However, I noticed that from mid to near full throttle, it pretty much stays at the same level of speed travel (the middle stage) only the engine simply spins faster unlike speeding up between these postions as it would do before with the bigger sprocket. So as you can see, there's a little bit of vice versa going on. These mowers were rated of a whopping top speed of 4mph, which is actually quite fast if you're behind this thing, but all in all I think it's safe to say that it has lost about 1mph from the top end.

2. Requires less movement of the throttle while going up inclines.
This one kind of corresponds with the one above as it is dealing with low end. But anyway, there is a little slope in part of our driveway to compare it to and when it had the 8 tooth sprocket on before, I used to have to throttle it up a little bit to get up it but now I noticed that it will pretty much go up it more on it's own with less movement of the throttle without slowing down.

3. Get's off the line quick!
Haha, yeah it has a bit of a jack rabbit start to it now, if you don't slip the clutch a little when you start off. When you first engage the drive, it lurches ahead but then quickly slows down into a steady pace. If you are not paying attention when you first engage it and don't slip the clutch, it can definitely take you by surprise as you'll get a nice tug on the bar if you if the rpm's are up. Before when it had the 8 tooth and you'd engage the the drive, it was smooth and slow but then would speed up into a decent pace whereas now it does the complete opposite at both spectrums.

So the big question remains in the end, was this all worth it? Absolutely.
Anyway, I'm really looking forward to adding up some hours of mowing on the machine this spring and summer to get to know it even better.

ere is a video of it in action with an explanation and walk-around of it beforehand. Would love to hear good or bad feedback about the video. I don't make YouTube videos very often so I can see that I'm not the best at holding the camera steady and also see I sort of held the camera in one position for the first part of the video while giving some explanation, so there are some things for me to learn and know not to do for next time.

The beast lingers in the distance.

See less See more
Very good video in my opinion Austen. :cool: I can see by it your feet are moving slower then what I recall from the other videos. ;)

I don't have a video camera myself despite once upon a time being an authorized servicer of the first RCA, Zenith, and Philips models when they first came on the market 1980's and 1990's. (Once they went to the VHS-C and smaller cassettes the parts got too darn small for me too work on. A watch maker I am not. :D)

I can take short videos with my digital camera. I'll have to try that sometime.
I can take short videos with my digital camera. I'll have to try that sometime.
Yeah, it's a handy feature. I wish the quality of the image was better though, to me it just doesn't look very clear and you also cannot zoom in and out while filming for some reason on mine which is strange. I'm sure the more expensive camera you get, the better quality of video it will take though.
Hey Austen, nice video. The walk around to show the various features and highlights was a nice touch. Your well deserved grin of satisfaction at the end says a lot. You can definitely see the difference in your pace. At least I can, knowing first hand how the King moves with the stock sprocket. I get that same sort of grin on my face when I start one of mine up too. Great job Austen!

How is your King these days?
He's sitting patiently waiting for me to get around to cleaning out the gas tank. The Bantam is doing the same. I have both tanks off and sitting in a corner of the garage, and when I get a free day I'm going to attack them both and get them going.

Your pictures, videos and stories keep me going until then.
I'm happy to say that today marks the one year anniversary of ownership for the King! It's been a great year owning it and it's come a long way since the beginning.

I remember the day that I went to pick it up and how exciting it was. I vividly remember following the gentleman around his house to the garage in the back, him opening the door and seeing it there for the first time! What butterflies I had!! After seeing and reading about them in ads and brochures for years and then to finally see one in person for the first time was simply amazing. I had dreamed of that day to come. It was so cool seeing it there and remember just walking around the dusty machine in circles mesmerized thinking to myself, "this is really it!"

To celebrate, I spent part of the day by mowing our lawn with it, ½ acre. I put at least an hour on it or more because I ended up going over it a few different times just so that I could use it longer, it just seems to want to hum a long all day. At this point, I don't have any more plans for it other than a complete restoration in the future. It runs and works great, but I have been noticing most all of the original engine gaskets seep or leak at least somewhere. I pulled the covers off today to have a look as I had been noticing some seepage by looking through them and ended up discovering the base gasket seems to be the main cause. I cleaned it all up, then fired it with the covers off and witnessed some tiny tiny little air bubbles arise every so often in a couple of areas. I think I'm just going to live with it for now and leave it all for the restoration one day, unless I choose to do it for a winter project. If things get worse quickly and the gaskets start developing severe air leaks to the point where it effects the running nature of the engine, then something will obviously have to be done before then.

See less See more
Happy Anniversary! Long live the KING!

Even with leaky gaskets, they still run and work. Gotta' love 'em. Life is good.
Well the new rims and tires arrived this week and everything looks great!

Boy, the rims are just about practically made for this thing amazingly! I couldn't believe it after I opened the box and test fitted one. It wasn't listed in the product description, but there is a notch already made for a grease zerk! I thought I was going to have dremel one out so that was definitely a pretty awesome surprise. It fits right onto the hub it like it was made for it, the center is dead on, however it's not really going to matter since they will be spaced out.

There are a few pretty minor things that needed to be done in order to make them work though.

1. Spacers:
They are however a lot wider than the originals, and I mean by a lot because they are even wider than the whole stock wheel and rim put together as a whole! Because of this, there won't be enough clearance for the tires so I will need to space them out about an inch. Right now I'm just going to use washers to get the clearance, measurements and everything right but I will eventually have some custom spacers made up for a cleaner, proper install.

2. Drill new ½" valve stem slot:
The valve stem hole is on the wrong side so I needed to drill a hole on the other "rim" so it can be mounted on the outside. I ran into this problem before when I had the new tires installed last year and the tire dealer installed the valve stems on the insides of the rims instead. I quickly found out they can't be mounted this way because they interfere with the hub.

3. Widen Stud Holes:
The bolt pattern for these rims was just about dead on with the stock rims but not quite, so I had to widen the holes juuust a bit.
Other than that, these things are gonna' mount right up and look fantastic!! It's exciting just to see how the rims will look when mounting one up. I'm still waiting for new inner tubes to arrive which is the hold up right now, but once they come in she'll have new shoes! :)

These things are tall compared to the stock size!!

Can you say DUB?! ;)

For comparison, check out the size of the stock wheel on the right.

See less See more
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.