Occ chopper engine vibration

[travis48g]

I just completed my 80cc two stroke occ chopper,however the bike vibrates so severly that it is unpleasant to ride.I have tried inner tube on the mount tubes,then in an attempt to make the mount more solid I tried bracing the engine mount(ebay mount) into the bike frame to make it completely ridgid.Neither of these things helped.I then began to suspect a balancing problem and that the internals of the engine was the source of the problem.However,when I took the engine off of my road bike(which does not vibrate at all)and installed it on my occ bike,the occ bike still vibrates just like with the other engine.So I am sure that the engine is not the problem.I am left with the assumption that the occ frame(combination of the fork rake, rear stay angle,or the box shaped frame with no triangulation)is not letting the vibration of the engine be cushioned by the bikes tires,instead the bike frame is trying to absorb the vibrations.My road bike will get a noticable bouncing of the front and rear tires while the engine is running(without my weight on the bike).I believe that on my road bike because of the much more ridgid triangulated frame design,the engine vibrations are more easily transmitted to the tires where the rubber absorbs the vibrations.I am wondering about mounting the engine on lawnmower type engine mounts(rubber cushions with studs molded in).Has anyone else had this problem on the occ bike or am I the LONERANGER!!!???

 

[davewelch2000]

yes my occ vibrates bad but once i get above 35 or so it stops i cut out the seat post to set the motor father back and cut the seat post tube in half and welded it right to the frame wraped some thick rubber arond the mount and used a spring to hold up end of exuast pipe still get vibe had a peveious occ with 4 stroke like 3 horse no vibe

 

[PatrickW]

Welcome to Mbc, Travis. I am certainly not an expert on 2-Strokes. but we certainly have some folks who are. Since you have introduced yourself, read thru the 2-Stroke Forum, and then ask some questions of the guys here who really know about them. In the meantime, the mounting bolts on dampers may be worth trying...sure can't hurt, and shouldn't cost a fortune.

 

[PatrickW]

(GEE WHIZ!!! 400 posts...Do I win the set of eternally sharp Ginsu knives, Tom??<GRIN>)

 

[ibdennyak]

(GEE WHIZ!!! 400 posts...Do I win the set of eternally sharp Ginsu knives, Tom??<GRIN>)

How bout an old Leatherman and a file with an MBC sticker on the handle.

 

[davewelch2000]

its like turning the bike in to a tuneing fork since the mounts end it makes it vibebrate if you could run the mount to the top of frame or connect the two toghter the vibe wold stop or else just have deal with vibe like the old harlyes