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!
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...