better late than never

[supermanotorious]

Well if life isnt one thing then its another, I'm out of control with projects here and there and who knows what raised the hair in my a$$ to breathe life in my lil' 50cc today mentioned in this post. I threw her on the work bench and first checked for spark and that was good. The gas tank had sludge in it so I disconnected it and sprayed it thoroughly with carb cleaner till it was sparkling, tried to start with no luck. I figured the carb was gummed up and boy oh boy was I right, even the fuel line was gummed up. I would compare the sludge to Dial liquid soap. The color was spot on but it was crazy thick like molasses. I cleaned out the line and cleaned my first 2 stroke carb and guess what- she fired right up! I love being able to do stuff that and owe a bit of the knowledge to my brothers on this forum. I took a couple celebratory rips down my troublesome neighbor's street and it was great. I'll need to figure out a throttle limiter so the kids can try it out.

 

[supermanotorious]

I've been toolin' on the 50 all day. Amazingly found all the parts to the pull start and reassembled it twice today, not sure if it's going to work but I'll check again after the fresh thread lock has a chance to cure. May have to order a new one. I picked up a generic muffler and welded it to the straight (obnoxious) header, the sound difference is pretty sweet. Added a kill switch which I salvaged from a hair dryer I took apart for the fireplace blower. I also re-did the fuel lines and once done, found out I needed to replace the primer bulb. Once ready to take some victory laps I almost immediately broke the #25 chain. It's mid-Sunday afternoon and I don't think I can get any #25 today, yet alone locally at all. SO HERE IS A NEW QUESTION! Does anyone know if its possible to replace the sprockets with #35? I cant even tell how to get the drive sprocket off.....

 

[supermanotorious]

So to convert to #35, I think I need this sprocket which will slip over the existing "axle"/transmission pinion. That being said, the existing pinion is bent so I think I need to replace it with this one. Now the challenge is to find a suitable #35 rear sprocket.

 

[supermanotorious]

Or, dare I jump up to #420 (which I'd just run #41) with this front sprocket and this rear one. Am I missing anything? It seems the front sprocket just slips over the pinion but I'm not sure how it is secured to it- set screw? If not I could weld them together.

 

[supermanotorious]

hmmm, I don't think those sprockets are designed to slip over the pinion at all now, what do you guys think?

 

[Axx3d]

That chain looks beat to begin with, id try a new pinion and chain prior to converting it. $20.00 bucks in parts ain't bad considering you've been able to salvage most of the parts already.

 

[ML-TOYS]

You just need to measure your shaft for pinion to fit on then find one if they make it

 

[supermanotorious]

Thanks for the suggestions, any idea how to unscrew the pinion? the engine shaft behind it seems to have a small groove that a special tool might engage to hold in place while the pinion is getting turned. Is that tool available, could it be made from scraps? I did some google searching but didn't find a tool that did that specifically. And do you know if the pinion is normal, or reverse threads?

 

[Axx3d]

Q. My Pocketbike front pinion (chain sprocket) has sheared
how to replace a pocketbike pinion

A. This is usually caused by one of three things, over reving with the brake on, chain too tight/loose or rear wheel mis-aligned. Firstly, you will need to purchase a new pinion, either the 6 tooth stock pinion which comes with the bike or a 7,8 or 9 tooth racing pinion. Take a look at our parts section. To replace the pinion follow these steps.

You undo the outer chain guard case of the pinion cover and remove. Put a large screwdriver or rod into the hole in the clutch drum at an angle, this catches the holes in the inner drum to ensure the clutch doesn't spin and turn the bike over! Normally, you would remove a 6 tooth pinion out of the bell housing by unscrewing it anti-clockwise using a 14mm socket.

If you can't get hold of the sheared pinion with pliers to unscrew it, this needs to be very very carefully drilled out using a small bore metal drill, don't touch the edges/sides as you'll damage the screw threads . Once removed this part, simply screw in the new pinion in clockwise using a socket wrench.

Taken from: http://paultheprogrammer.hubpages.com/hub/Minimoto-Maintenance

So it seems like you could lock the clutch in place and get a socket to fit over the sprocket/pinion and back it out...

 

[supermanotorious]

I appreciate that but what you see is what you get, there is no clutch as I can tell but is it possible its behind the seal??

 

[Axx3d]

You may have to pull the bolts off the cover to see what needs to be done.. I can see 3 on the bottom of the pict you have.. There is some form of clutch under there.. Or just throw a socket on it and smack it.. it may break loose..

 

[mental74]

The transmission should pull off of the motor & it should have a clutch that looks similar to this.

 

[supermanotorious]

sure enough clutch was behind the cover, I cant for the life of me get the clutch bell to stop spinning while I try to unscrew the pinion gear, UGH

there is no way to stick a screwdriver in the holes

Please help!

 

[jeeperjoel]

looks like you could put a socket on sprocket (hee hee that rhymed), and on nut inside, remove shaft, then put shaft in vise....

 

[Axx3d]

Well considering the pinion is no free wheeling on the cover n bell housing there has to be a way. Do you have a impact driver? Maybe hit it with that. Any other ideas i have would bend the clutch bell..

 

[supermanotorious]

the nut inside the bell comes off, the dang bell is welded to the shaft

 

[supermanotorious]

these are pretty helpful links:

http://www.pocketbikeplanet.com/showthread.php?t=16242

http://www.pocketbikeplanet.com/showthread.php?t=5742&page=2

 

[supermanotorious]

On the fence whether or to strip it down, clean and paint it, I did get some small inspiration to clean the rear sprocket and make it my classic "gold". Again, can anyone tell me why I would paint the sprocket gold?

 

[porsche930dude]

that shaft is supposed to be held with a mini spanner wrench while you unscrew the sprocket with pliers or a socket. you can easily make a spanner out of scrap metal

 

[supermanotorious]

what a coincidence, I tried welding a small piece of metal to the spanner wrench that comes with an angle grinder as to make a tool that slid into the notch on the shaft, I never considered using the wrench as it was designed

I went ahead and ordered some #25 chain yesterday, I'll just keep using the bent pinion for now, I think the other forum mentioned its ok if the pinion is bent so long as the rear sprocket is straight

that shaft is supposed to be held with a mini spanner wrench while you unscrew the sprocket with pliers or a socket. you can easily make a spanner out of scrap metal