strange engine vibration....

[babulin2002]

hi all,
i have an '94 r1100r, and since one year or so the engine peorformance has been decreasing. vibrations in higer revs (i did valve adjustement and throttle body sync, only slight improvement. oil level is not too high either.), and the vibrations come and go. mostly come, though i happens often that the bike goes reasonably smoothly initially, but then starts vibrating and keeps so. then i switch off the engine and after starting again it feels better, only to start vibrating again a while later. just as if things were loose inside. i used to have slight vibrations around 4t revs, which is normal i hear, and everywhere else the vibration would decrease. i could go 190 km/h no problem. now the vibration doesn't usually go away after crossing the 4t revs, only increases, and the engine seems to have a lot of friction to fight with, so that at 150 km/h it feels like it will fall apart any second (and that is pretty much the top speed now ). sometimes i rev up to 5000 and it goes pretty smooth, and then vibrations kick in upon decelerating. basically, it can appear at any moment. again, intuitively, it feels like the moving elements insisde have loose fits, and the "natural" vibrations at around 4000 revs can kick it out of proper position or something. is really frustrating and i was wondering if anyone had a similar experience? the engine has 80000 km on it, so i'm afraid it can mean the end of this engine is approaching...

[OU812]

I hope you are wrong about the end of the motor. My r1100 has 54K miles and at 80mph it has a vibration also. i have yet to check the valves and sync the TB's. Hoping that will help. Keep us posted.
Steve

[BalancePoint]

hi all,
i have an '94 r1100r, and since one year or so the engine peorformance has been decreasing. vibrations in higer revs (i did valve adjustement and throttle body sync, only slight improvement. oil level is not too high either.), and the vibrations come and go. mostly come, though i happens often that the bike goes reasonably smoothly initially, but then starts vibrating and keeps so. then i switch off the engine and after starting again it feels better, only to start vibrating again a while later. just as if things were loose inside. i used to have slight vibrations around 4t revs, which is normal i hear, and everywhere else the vibration would decrease. i could go 190 km/h no problem. now the vibration doesn't usually go away after crossing the 4t revs, only increases, and the engine seems to have a lot of friction to fight with, so that at 150 km/h it feels like it will fall apart any second (and that is pretty much the top speed now ). sometimes i rev up to 5000 and it goes pretty smooth, and then vibrations kick in upon decelerating. basically, it can appear at any moment. again, intuitively, it feels like the moving elements insisde have loose fits, and the "natural" vibrations at around 4000 revs can kick it out of proper position or something. is really frustrating and i was wondering if anyone had a similar experience? the engine has 80000 km on it, so i'm afraid it can mean the end of this engine is approaching...

Vibration is essentially always present in some degree, and the extent to which you can feel it is the measure of its intensity. I would pull the spark plugs. If they're both looking good, warm up the engine and obtain an oil sample. Oil analysis will alert you to any metal in the oil from bearings, rings, etc that signal serious bottom-end problems. Also, how do your tires look? At a certain stage of wear, they can cause a lot of vibration problems, or they may have thrown a weight. Also, wheel bearings front and back. Play? Paralever bushing?

[babulin2002]

Vibration is essentially always present in some degree, and the extent to which you can feel it is the measure of its intensity. I would pull the spark plugs. If they're both looking good, warm up the engine and obtain an oil sample. Oil analysis will alert you to any metal in the oil from bearings, rings, etc that signal serious bottom-end problems. Also, how do your tires look? At a certain stage of wear, they can cause a lot of vibration problems, or they may have thrown a weight. Also, wheel bearings front and back. Play? Paralever bushing?

i know vibration is there always, just that i used to have much less and not variable, and the ride was much smoother. now i can feel the engine struggling. tires are new. i recently changed all oils, and didn't see anything suspicious. the strange thing is the variation of the vibration, that it kicks in. like said, it can feel ok just after start of a ride, then after going to high revs it sometimes remains even if i decelerate and even stop the machine. usually after switching off the engine (gas station for example) and then starting again it feels better, initially that is, untill i rev it up again. i thought maybe it's temperature related, but it doesn't seem to increase gradually, just appears suddenly. i do belive it is the engine, the bike rolls nicely in idle, but decelerates rapidly if in gear and i let go of the throttle. i kind of suspect the dynotab fuel additives, but am not sure how they did it. i used them a year ago or so, and initially it was better, i got the valve clearance & TB synch done and the ride was smooth. the bike started to burn oil though, and the various rubber tubes started leaking . then the oil level was low afor a while till i noticed it. and since then it just gets worse and worse. since these oil additives basically dissolve all the dirt accumulated on the parts, i can imagine that the piston seals got affected and started leaking some oil etc. the same with rubber tubing, which i simply replaced. could the vibration possibly come from the pistons? (obviously they are a major moving part of the engine and the source of vibration) what else could the dynotab affect? i am no mechanic, i am not stupid either but with zero experience i simply am not able to pinpoint the possible causes. i will check the wheel bearings to be sure, but i strongly suspect that's not it. thanks for the reply to all!

[OU812]

I am just starting to ride mine and I have owned 2 other R1150R's.Those never felt like this baby. I have to say the vibration on mine is at the 3500-4000 RPM range, any gear. Not noticed any other time. Recent fluid changes for mine also.

[babulin2002]

just an update: it turned out that part of the problem was the high ambient temperature (>30 deg C) , since i'm using 10W40 oil. now that the temperature dropped down to 20-something it rides smoother. still vibrates though, but not as bad. rode it just two days, but didn't notice the variation in vibration, which was worrying me. so maybe there's hope afterall have to start using 15W40, or move north
cheers!

[OU812]

I did the valves(only rt side exhaust needed adjustment )and TB sync with MAD1150 . Big difference for mine. I am in love again.