1 vibration is unbearable on newly acquired '91 k100rs..... i'm ready to dump it!!! Sun May 20, 2012 10:04 pm
browe58
active member
i thought i wanted a k bike and got a good deal ($1800) on a 91 100rs w/ 85k miles in really nice shape. recent tune job, a few odds & ends, & fluids replaced. now i regret it. i heard about the vibration but the po assured that his didn't vibrate. he's either full of it or never got it beyond 4k rpm. i have an '01 r1200c so i'm familair w/ bmw build quality. the 100rs is no exception. starts easy, idles smoothly (at around 1250 rpm when fully warmed per the tach; trying to get it lower....... IS IDLE ADJUSTABLE ON MOTRONIC???) and pulls like freight train w/ no hesitation whatsoever. i'm confident i have no air leaks and that throttle bodies are synched properly. but beyond 60 mph or 4k rpm the bike feels like a jap 750 cc bike. just way too buzzy for my taste. everything is tight, new tires, bar backs, bar end weights, corbin seat, remus exhaust. i've read all the tricks to minimize the buzz and most are not an issue on this bike. i just don't want to tear this thing apart and not get rid of the vibration. so i;m doing the easy stuff first. i can't image this bike doing 130-140 mph as claimed ny bmw. i'm willing to do a few things to see if it improves; otherwise, i'll have to dump it:
1. what plugs are you guys using and at what gap. on my r1200c i replaced the expensive oem's w/ cheapo autolites and it made a huge difference.
2. smooth shifting up & down so i know the clutch splines are good. would driveshaft splines cause vibration above 4k rpms? will need rear brakes soon if i keep it so when i have the rear apart i'll check out the splines.
3. will timing adjustment help dampen vibration? retard or advance? can i use basic timing light? i've read not to mess w/ it but have seen posts where guys claimed it help.
4. i'm leaving valve adjustment for last. right now it idles smoothly (no noticeable ticking) but when i take off in 1st gear at low speed i can hear something ticking/slapping around (if i'm not mistaken, i'm also getting some feedback from the clutch lever) which goes away once i hit 2nd & 3rd it smooths out and disappears. what the hell am i hearing? is that normal for the k bikes?
thanks in advance for suggestions. peace.
bill
1. what plugs are you guys using and at what gap. on my r1200c i replaced the expensive oem's w/ cheapo autolites and it made a huge difference.
2. smooth shifting up & down so i know the clutch splines are good. would driveshaft splines cause vibration above 4k rpms? will need rear brakes soon if i keep it so when i have the rear apart i'll check out the splines.
3. will timing adjustment help dampen vibration? retard or advance? can i use basic timing light? i've read not to mess w/ it but have seen posts where guys claimed it help.
4. i'm leaving valve adjustment for last. right now it idles smoothly (no noticeable ticking) but when i take off in 1st gear at low speed i can hear something ticking/slapping around (if i'm not mistaken, i'm also getting some feedback from the clutch lever) which goes away once i hit 2nd & 3rd it smooths out and disappears. what the hell am i hearing? is that normal for the k bikes?
thanks in advance for suggestions. peace.
bill