My 400 scrambler just started acting like a bike with a manual transmission would if you left it in second gear,tranny mechanicking is new to me,looking for suggestion on what else may cause my problem,or some insight as to the complexity of transmision,also suggestions on aftermarket transmission,it's about the only thing not changed allready.

 

Remove the 4 bolts that hold the left footrest down, and all the bolts on the belt cover. You will either have to cut the zip tie on the breather boot for the belt cover, or remove the snorkel when you take it off. If the belt cover doesn't pull away from the engine easily, you probably forgot a bolt, or there is a clip holding it. The clip is hard to see, just a spring steel (black) clip that clamps on the lip of the belt cover, kind of to the back of the cover.

With the cover off, look at the belt. Does it look OK? Does the pulley look OK? The front pulley is set up in such a way that the outer half moves inward to squeeze the belt as throttle is applied. Try wiggling the outer part against the inner part, to see if it is loose. You will notice 3 'arms' in the front pulley. Where the 'arms' slide (between the moving and stationary parts of the pulley) there should be 6 teflon 'buttons'. Be sure they are all there.

If nothing obvious is wrong, start the engine in neutral, and rev it up some. The belt shoud be grabbed by the front pulley, and as the engine revs out, the belt should climb up the pulley clear to the top. If it doesn't, something is wrong.

Try this, and report back what you find & we can go from there.

Farmr

 

that is pretty much word for word where I started the buildup on this bike has about 20 hours ride time and everything looks about 20 hours old,I put it on blocks & ran it in gear,out off gear everything seemed ok acceleration might be slow but it's hard to tell with it on blocks,there are no noises & nothing visually wrong, the rear wheels turn easily by hand,engine runs strong,thats what has me leaning towards transmission problems I'm still not sure though.

 

Take the secondary clutch off and take it apart and check the buttons that the helix slides on. These will effect the back shift .I had one break off and act just like you are saying.

 

That sounds like a good idea,it didn't even enter my mind and I'll bet that's it,thanks

 

Thanks to ftwflh (Brad) I now have a pretty fast 4 wheeler back on the trails, thanks I was about a day away from pulling tranny, I'm glad I got on forum.

 

Your very welcome thats what we are here for.