HELP! '82 GS650GLZ with serious vibrations at 5000 rpm

[JonOrlando]

Hello!

20 years ago, I was the proud owner of a '82 GS650GLZ. That bike was sold for parts after it was laid down. Now, I have recently bought a cherry '82 GS650GLZ with less than 2000 miles. Almost identical to my first GS. Call it nostalgia, I'm hooked again...

The bike has been completely overhauled and is in near perfect condition for a 25 year old bike. Here's my issue: when accelerating, the bike has a serious vibe in 3rd and 4th when approaching 5000 rpm. Vibes go away in 5th. Anyone out there experienced similar vibes during acceleration? Any suggestions?

Thanks!

[rphillips]

Scratching my head twice. First scratch, sounds funny it vibraets only in 3rd & 4th. Is the vibration a buzz, like eng vibes, or a slower vibration, like wheel out of balance?? Second scratch, What in the world would justify a complete overhaul on a 2000mi GS engine???

[JonOrlando]

I only notice it in 3rd and 4th. It might be there in 1st or 2nd, but I don't rev it that high in the low gears. Not there in 5th. As for the overhaul, 15 years in storage will take its toll...

[salty_monk]

what about stationary compared to moving? That would isolate it to either engine or something loose or something that moves when moving such as a wheel or forks.

[chef1366]

Bad tires? Bent rim? Synchronized carbs?
My guess would be the non synced carbs.

[t3rmin]

Push in the clutch and let the engine rev down at speed to see if it's chassis or engine.

I've got a nasty vibe in my 650 motor, too. Doesn't appear to be carbs as they're synched nicely. Problem increased after new flywheel, so I'm gonna try having it balanced at a machine shop one of these days.

[KEITH KRAUSE]

Did you correctly torque all engine mounts, swingarm, bars, forks and shocks, front and rear axles?