Engine vibration

[texasrices]

When cruising down the road, everything sounds and feels great, until I get to 70 MPH. From 70 mph to 80 mph it feels like the bike is beating itself to death. Over 80 mph it smooths right out.

 

Put in a tankful of Seafoam, changed the spark plugs and wire caps. Changed the oil and filter and synced the carbs. Replaced the fuel filter last year.

 

The only solution I can think of is it probably needs a valve adjustment. According to the manual, it should have been done at 26K and I have just over 31K on the bike.

 

Does this sound right? In reading the manual it is a job that I don't think I can handle by myself.

 

Any and all suggestions appreciated!!

 

:confused24: :confused24:

[Mavrick]

I changed the plugs on mine a couple of months ago and started noticing a vibration about like you describe. A couple of weeks ago I bought another set of plugs and changed them out again. When I pulled the wires off the old plugs I noticed one of the wires was not seated very good. I put the old plugs in and made sure they were seated good and the vibration went away.

 

I am not sure if I had a bad set of plugs or the wires just were not seated good.

 

I have also heard you will get a vibration if you overfill with oil.

 

Hope this helps.

 

Mike

[BuddyRich]

I did my valves at 31k and they were in good shape. I would think if it was engine that you would get the vibration at the same rpm no matter what gear your in so speed would not be as big of a factor. I would look at the drive shaft, rearend, or wheels. Since it seems to be at certain speeds instead of certain RPM's.

[V7Goose]

Are you sure it is engine vibration? If it is, you should have that problem at the same RPM in any gear. If it ONLY happens at the speed you stated in top gear, then it almost certainly is not the engine. My bet would be tire balance.

Goose

[Guest Bigin]

I also am trying to diagnose new vibrations on my first gen handlebars and pegs. Its bad enough to numb hands and tingle feet. It is the engine, I can pull in the clutch at speed, idle engine and it is gone, rev engine up to above3500, it comes back, hopefully engine mount rubbers, not the engine itself. Will sync the carbs next week, I know they are not even close though the bike runs well, hope this helps, if not will be looking at all engine and frame bolts tightness and condition of rubber mounts, after that will start worrying about engine internals, maybe in area of clutch basket as vibrates strongest in that area (which makes me think a sync will help). My other VR had no trace of this, even with the hard rubber stock grips (sold it last month) so I know it needs to be addressed. Good luck with yours.

[pegscraper]

Wow, Seafoam didn't fix the vibration? I can't believe it. I thought that stuff was supposed to work miracles.

 

I would also look at tire balance.

[Condor]

Syncing the carbs will make an engine run smoother.

Gets all cylinders to pull together. :dancefool::dancefool:

[GeorgeS]

Run at the same RPM in forth gear, lower speed, see what happens.

 

My bet would be tire balance.

[Guest Bigin]

Now have synced the carbs, were way, big difference, but still have the tingling in pegs and bars. Pulled clutch, nothing obvoius, couple plate marking not aligned, fixed that, reinstalled everything, still there but less now. Mounts I guess are next.

[Condor]

Looks like you've taken care of most of the buzz, but you'll probably never get rid of all of it. There'll always be some unless you get the engine and drive train blue printed, and I'm not sure that would get rid of it 100%.... You might think about foam grips if you don't already have them?? Try new plugs just because. If one cylinder isn't pulling like the rest it could cause a vibration. Oh yeah... and Sea Foam the 'H' out of it.....

[Guest Bigin]

Condor, you a probably right, have to live with it. Have the foam grips already. Its not a miss, too high frequency. Probabaly would not have been so noticeable if my 91 which I sold recently was perfectly smooth in this area, had twice the mileage, almost 100k and had the hard rubber grips to boot! As long as it is not something failing im going to just ride it! thanks