Vibration - mild - in R1100RT

[tomrinbellingham]

I'm not a mechanic, but I like it when it runs smooth. I've got 2 R1100RTs; one is Fernando's old bike - a 1999 with now 100K miles on it. The other is a new to me 1997 with 50K miles on it. Both seem to have been taken care of mechanically and cosmetically better than average.

I rode Fernando's old bike around Europe this summer for 6 weeks and about 6K miles - no vibration at any speed. The '97 seems to have a very mild vibration which gets more noticable at about 65mph and seems almost as bad as a Harley at over 100mph. It isn't tires/wheels - at high speed, when I put in the clutch and idle the engine, it runs smooth.

The vibration isn't accompanied by any knocking noise or anything that leads me to think it might be this or that.

Anyone gat an idea what it could be? What tests I could do to track it down?

Thanks for any help.

Tom

[Boffin]

It is probably throttle sync. I know I can tell by feel when my 1150 is even slightly off perfect synchronisation. The 180° engine configuration exagerates any difference in setup.

 

Andy

[T__]

I'm not a mechanic, but I like it when it runs smooth. I've got 2 R1100RTs; one is Fernando's old bike - a 1999 with now 100K miles on it. The other is a new to me 1997 with 50K miles on it. Both seem to have been taken care of mechanically and cosmetically better than average.

I rode Fernando's old bike around Europe this summer for 6 weeks and about 6K miles - no vibration at any speed. The '97 seems to have a very mild vibration which gets more noticable at about 65mph and seems almost as bad as a Harley at over 100mph. It isn't tires/wheels - at high speed, when I put in the clutch and idle the engine, it runs smooth.

The vibration isn't accompanied by any knocking noise or anything that leads me to think it might be this or that.

Anyone gat an idea what it could be? What tests I could do to track it down?

Thanks for any help.

Tom

 

Tom, how does the engine feel if you just free rev it in place?

 

In any motor vehicle line some vehicles just vibrate or shake more than others.. Sometimes due to basic engine balance (or lack there of),, or clutch part imbalance,, or combustion frequency related, or even how the engine is tuned (like even valve settings, or perfectly balanced TBI units,, or cylinder compression variations,, or even such things as loose engine mounting bolts or loose alternator attachments.. Even a flopping alternator belt can transfer engine vibrations.. A fuel injector that isn’t performing can add to vibration also..

 

Maybe check the easy stuff first, like loose engine & alternator bolts,, then do a good TBI balance & good valve adjustment,, then look for things like center stand contacting the catalytic converter (or pipe).. Look for loose muffler mounting parts,, look for loose steering head bearings or rear swing arm bushings..

 

About all you can do is go through each area & verify it is correct..

 

Twisty

[tomrinbellingham]

Just sitting there it doesn't run so smooth either. Lots of suggested possibilities between you and Boffin. I'm wondering... the guy who owned it before me was a cop and he sounded like he didn't speed. Could these symptoms of mild vibration be from carbon build up? How do I test for that? I could just go out and do a little racing around, but the first two days I had this thing, I got two speeding tickets. I'm driving like an old lady for awhile - as long as i can stand it.

Tom

[Ozonkiller]

Watch your oil level closely. I keep my oil level just barely visible in the glass. If it is any higher than a third of the glass I get a slight vibration at highway speeds. It all started several years ago when I topped off the oil while on a trip from Arizona to Nova Scotia. Here I was several thousand miles from home and my RS developed a slight vibration. It took several years of chasing the vibration that would come and go before I nailed it down to that. My bike uses no oil, so I'm perfectly comfortable running it that low.

 

Good Luck,

 

Tom