lots of vibration in new motor

[overrevtricky]

Just finished breaking the beast in with new top-end, trued/welded crank, new gaskets.....blah blah!

Shee's vibrating a bit more than before, could this be due to the truing of the crank? maybe its off a little? thanks alot as always fellas.

[rdzbangshee]

Just finished breaking the beast in with new top-end, trued/welded crank, new gaskets.....blah blah!

Shee's vibrating a bit more than before, could this be due to the truing of the crank? maybe its off a little? thanks alot as always fellas.

i have herd that happens with stock cranks go for a nice aftermarket one . the vibration will tear up your engine spin a bearing and destroy your new rebuild.

[Sandfrk33]

Do you feel a vibration at all RPM's?

[overrevtricky]

It doesn't do it in the power, just the normal-feeling vibration. Its the low-end that gets it.

[Larry's Shee]

Double check all your motor mount bolts and look at the rubber insert in cases.

[tundish2800]

Did you put the metal shims in between the motor mounts a case? I had that same problem and it cleared it up,

[locogato11283]

mine vibrates at idle. with some throttle the vibration mostly goes away.

[sleeper06]

They all vibrate,who trued your crank?I have had set backs with cranks that were supposidly trued,luckily I check everything.When I put iot in the v-blocks it was .006 out.Many things can happen when welding a crank,I have to put almost 140amps into it just to get it hot enouph to fuse.I have checked true with crank in bike its just not easy

[live2beel]

They all vibrate,who trued your crank?I have had set backs with cranks that were supposidly trued,luckily I check everything.When I put iot in the v-blocks it was .006 out.Many things can happen when welding a crank,I have to put almost 140amps into it just to get it hot enouph to fuse.I have checked true with crank in bike its just not easy

 

They seem to vibrate a little more when you go up in stroke size also.

[AKheathen]

first, check the simple things like carb sync and misfires. then, i would do a compression and squish check on both sides.....i chased one when i first got mine, thinkin "no way they vibrate that much. it was actually a chewed up squish in the chamber from a previous ring snag causing a compression imballance. also, make sure the flywheel is square on the crank and seated properly.

[overrevtricky]

Took it for a good spin today, vibration sure goes away when the throttle is anywhere but idle. It's also only on the right side. I looked at each pipe to stinger connection sitting on it, and at idle its only the right side that vibs not-so-normally!

[toolman]

Try loosing all of the engine mounting bolts. Start the engine for a few seconds then retighten all of the bolts. You might have something in a bind. I have done this and it makes a big difference.

[overrevtricky]

Try loosing all of the engine mounting bolts. Start the engine for a few seconds then retighten all of the bolts. You might have something in a bind. I have done this and it makes a big difference.

 

 

Hmmm, that is certainly interesting. I've got nothing to loose so I'll give her a whirl.