cant line up sprockets, 4 stroke

spiderskzes

Member
Oct 10, 2012
45
0
6
san diego
I'm really lost here guys help would be awesome. I have a hs 4 stroke motor with the grubbee 4g tranny with the 100 tooth sprocket and no freewheel bearing. I was running a 50 something sprocket in the back and was converting to a 36t sprocket. Once I got the 36t sprocket on the rear wheel I trued the sprocket bolted it to the frame , and cut the chain to good length.once I mounted the chain it would try to jump off the sprocket in the front (the 12t one I think) whenever I spun the wheel. When I looked at it from the back the 12t sprocket looked like it was too far left because that was the side the chain was jumping on. I unbolted the motor and slide it as far right as I could but the chain still jumped. Since I figured the rear 36t is farther right and I couldn't move the motor over anymore I added three washers to the nine bolts that connect the 36t to the rag joint. I put these in between the sprocket and the outside rubber piece. So this now pushed my 36t to the left about 1\3 of an inch . Once I got the chain back on it did the same thing jumping and trying to derail from the 12t sprocket. I looked from the back and it still looked like the 12t is too far to the left. Any suggestions on how to line these up? Is there another way to move the 12t sprocket besides shifting the motor on the mount? And is it even safe to use more washers to push the 36 t sprocket farther away from the spokes? Its frustrating because my 50t sprocket had no issues and it seems like they where mounted in around the same place.thanks:-||
 
Last edited:

MotorBicycleRacing

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Jul 28, 2010
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Good choice on gearing your bike up so you don't over rev it at 35 mph.

Photos of showing the chain line would help including sighting down
from the rear.

Was your 50 tooth sprocket dished? how about the 36 tooth?

Are you using a chain tensioner? Is it lined up with your chain?

Is your new 36 tooth sprocket warped?
centered on your wheel with little run out.
 

spiderskzes

Member
Oct 10, 2012
45
0
6
san diego
The 50t was dished the 35t is not. that's the reason i put the washers in you can see them in of the pictures. i do have a tension er. i noticed the rear sprocket sends the chain to the 12t at an angle would i have to bend this or just turn it around?
 

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spiderskzes

Member
Oct 10, 2012
45
0
6
san diego
Good choice on gearing your bike up so you don't over rev it at 35 mph.

Photos of showing the chain line would help including sighting down
from the rear.

Was your 50 tooth sprocket dished? how about the 36 tooth?

Are you using a chain tensioner? Is it lined up with your chain?

Is your new 36 tooth sprocket warped?
centered on your wheel with little run out.
any help would be awsome