running rough

[Roadrunner001]

my 660 Skorpion seems to of started vibrating more than it used too

seems to idle fine, it's only once I'm moving that it becomes evident, could the chain & sprockets be needing replaced? I'm not very mechanically minded but the place I used to take the bike for maintenance has closed down, now I'd have to travel about 50 miles so need to try and do more myself

[jimc]

Does it do it coasting with motor off? Any particular speed (tire balance)?
Put the bike up on the center stand manually spin the rear wheel and check out how the chain appears to run, look for tight/loose and the condition of the teeth, check rear wheel axle alignment marks.
Spin the tires & look at that too.
Also, does the front & rear suspension seem to move OK or is there any binding?

[DEmark]

Check the motor mounts. Are the bolts tight? Are there cracks in the brackets?

[Roadrunner001]

it only happens when the engine is under load, I've checked the chain and it appears to be a little loose but not too bad, I'm gonna adjust it at the weekend and see if that cures the problem

[DAVID THOMPSON]

check the front sprocket NUT and locking tab
both my saxon tour and rt125 have came loose in the last 2 years