2006 LF200GY-2 Engine/drivetrain vibration? Excessive?

[moresnow]

Seems to be getting worse the more I ride it? Under load you do not feel it at all. Cruising at little or no load it is becomming scary. Almost feels as if its pulling down on the motor as it comes and goes at different rpm? Almost a harmonic balance issue? I have yet to tackle valve adjustment. I understand this is a pushrod type motor. Is there a adjustment that I need to address otherwise? Runs great other than being very tough to start when warm. Starter had come loose shortly after I purchased the bike. I tightened it back up and it no longer will engage? Any help would be appreciated. Thanks

[FastDoc]

Your valves may need adjustment but that's not likely the problem here.

Usual culprits are loose or missing motor mounts/bolts. Very common. Chain too tight or too loose (less of an issue) can contribute. Less common would be out of balance/round wheels/tires, or maybe a defective tire or wheel.

Start there.

[moresnow]

Originally Posted by FastDoc

Your valves may need adjustment but that's not likely the problem here.

Usual culprits are loose or missing motor mounts/bolts. Very common. Chain too tight or too loose (less of an issue) can contribute. Less common would be out of balance/round wheels/tires, or maybe a defective tire or wheel.

Start there.

When I picked up the bike it was missing a motor mount bolt. Another was broken and another was loose. Quite a find... Anyway all have been replaced or tightened. The tires are worn and need replaced. Having a hard time believing the tires are the culprit but I could be wrong. The vibration seems to be getting worse without significant additional tire wear. Chain adjustment could be the culprit. Seemed the chain was tight when I parked and now its loose? Odd. I've adjusted it twice. Seem to be chasing the chain adjustment. Possibly a worn bushing making it inconsistant? Rear sprocket is floating also. Assuming it should? Thanks

[FastDoc]

If the vibration goes away while riding and you pull in the clutch it can't be the chassis things Ive mentiond and it must be in the engine/mounts.

Now I'm wondering if there is something wrong with the motor that it undid it's mounts in the firstplace. Is your engine counterbalanced?

[moresnow]

Originally Posted by FastDoc

If the vibration goes away while riding and you pull in the clutch it can't be the chassis things Ive mentiond and it must be in the engine/mounts.

Now I'm wondering if there is something wrong with the motor that it undid it's mounts in the firstplace. Is your engine counterbalanced?

We have a potential answer. Rear most engine mount bolt had been replaced with a chunk of 3/8" ready rod! O.D. is to small which let the motor move around until it broke a mount location. Appears the bolt should have been a Metric #12. Anyway the better fitting bolt is on the way. Removing the motor to repair the broken mount is tomorrow mornings job. The story continues! Thanks for the heads up.

[FastDoc]

Sounds like you've got it!

BTW when I repowered my 1984 XR200 with a Lifan 200cc I also used an all-thread SAE bar of some sort for the bottom rear mount, IIRC. In my case it worked fine and I got away with it but who knows over time?

[Weldangrind]

If the mount calls for a 12mm bolt and you can't find one, better to drill it out to 1/2", which is just slightly larger. Better surface contact than all thread / redi-rod.

[moresnow]

Found a gent on ebay who strips bikes in a town 45 min's away. Robbed a bolt out of his junk pile. Installed and it seems we are good to go. Whew. Buddy of mine is building a Honda CX500 to run at the salt flats in the 500 class. We picked up a set of heads today for him also. Stopped at Dave Feazels custom Harley shop to visit also (research him). Good time all around.

[edtardo]

My bike had a similar vibration up until the the frame broke in half. Recently my chain busted and when I went to replace it I found the rear bottom mount bolt was missing.

[SpudRider]

That's probably why the frame broke, ET. I suggest every hondoid owner should check all his engine mount bolts, and secure them with red loctite. 8O

Spud