Starting minor projects V1

[nectarsis]

http://www.oldminibikes.com/forum/g...bikes-woooooo-projects-good-times-coming.html

Today I FINALLY had some time to "work" on Duster chopper. Took off the motor, CLEANED it, motor plate, tires (front is pretty dry rotted). While it was off I changes the oil...or what I THINK was oil lol. I noticed the motor plate had been cut where the chain runs,a small crack forming off one of the front motor mount slots and at one time it had a chain tensioner. Also found the spring for the scrub brake is shot.

After everything is cleaned, and dried up I bolt it all back up, fire it up and RIDE...for 5 minutes. When I bought it the old owner told me the chain pops off, and I needed to push the motor forward (which I did). Second run up the hill outside our house the chains pops off :censure::cursing::censure::cursing: I was actually somewhat proud as this is the first bike I've worked on and haven't touched a small motor since early high school (and remember next to nothing lol).

Small crack forming

Remnants of chain tensioner

Shot scrub brake spring

Bolt's are broken/twisted

A few questions (forgive my noobness).

1. Is there anyplace to replace those 2 "motor stops"?

2. Can anyone suggest a good place/style for the scrub brake spring?

3. Is there a chain tensioner that could screw into the old mount (no welding)?

4. MOST important, the chain issue. Possibly need to take links out? As far as I can tell the engine can't be any farther forward.

I appreciate any help/ :smile:

 

[125ccCrazy]

A few questions (forgive my noobness).

1. Is there anyplace to replace those 2 "motor stops"?

2. Can anyone suggest a good place/style for the scrub brake spring?

3. Is there a chain tensioner that could screw into the old mount (no welding)?

4. MOST important, the chain issue. Possibly need to take links out? As far as I can tell the engine can't be any farther forward.

I appreciate any help/ :smile:

The adjusters look good except the bolts, I'd buy new bolts (look like 5/16") and just replace them.......

For the brake spring I'd look at your local harware, they usually have a spring assortment or Lowes, Home Depot usually have springs in thier harware section, may not find an exact spring but one close enough to get the job done..

Most aftermarket chain tensioners require some sort of welding....if I had the bolt spacing I could probably fab something up..


You should have about 1/2" play up and down on the chain when it's tight, if it's excessively more than that you may need to remove a link or two or better yet a new chain if that one is fairly old as it's probably stretched out...

Also make sure the rear sprocket and clutch gear are inline, if they are not lined up that will cause a chain popping problem.... Clamp a good straight piece of 1/2" angle iron or even a metal level to the rear sprocket, the other end should lay flat against the outter edge of the clutch gear.... With that crack and the notch cut in the engine plate the plate may be flexing under hard acceleration causing the engine to lean over and throw the chain... Without having the bike in front of me these are just different senerios to the problem.... it may be one of the above problems or a combination of a couple...