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View Full Version : rebuilt, real bad vibration


h400exrydr
09-03-2007, 08:32 PM
well i got my quad all back together. what i did was gusset the frame, powder coat it. for the motor i got a brand new crank, brand new cylinder, brand new piston, brand new valves. basically the whole motor is new Honda stuff. But now that i fired it up, it has a REALLY BAD vibration. the vibration isnt there in low RPM's or high RPM's just mainly the mid RPM's. im not really sure what it could be. All the motor mounts are tight, im just not sure what it could be. PLEASEEEE HEEELLLPPPP!!! i really dont know what it could be. does the new crank have to be balanced? im really lost. thanks!
JessetheKid
09-03-2007, 08:46 PM
im not sure if this could be it but i had a similar problem with my 250r and it was timing i would check into that
h400exrydr
09-03-2007, 08:48 PM
that was wat i was thinkin. like maybe the timing chain could be off one tooth or somethin? i hate this.
Turboderf
09-03-2007, 08:58 PM
do these 450 have a balance shaft ?
GPracer2500
09-04-2007, 01:04 AM
Yes they do. Make sure the punch marks on the balancer drive gear, driven gear, and balancer weight itself are aligned. If the balancer is out of time with the crank, I don't know if it would cause the RPM specific problem that is being described--but it might. Definitely check it.
09-04-2007, 06:26 AM
I would have to agree with the counter balancer being off.
hendershot106
09-04-2007, 07:09 AM
been there-- made the same mistake---- its definitely your counterbalancer -- just like gpracer said---- make sure ur punch marks line up------
JessetheKid
09-04-2007, 07:58 AM
yea, because on my 250r the timing was off on the counterbalance and it was hard to even hold on to the bars it vibrated so bad
h400exrydr
09-04-2007, 11:24 AM
ok so if the counterbalancer is off the how do i readjust that? it is the part on the right side of the motor right? the side with the clutch? thanks for all the help guys!
hendershot106
09-04-2007, 01:46 PM
u have to pull of the whole clutch outer cover-- and re align the dot marks with each other--on the gears towards the front of the motor-- one looks like it has a weight on it---- if u have any doubt- have ur local honda dealer copy that page from a manual for u or just buy a manual---