Hi, I have a k100rs 1990, problem im having is when the bike is cold in first gear on take off the driveshaft/swingarm does some serious shuddering, when the bike is warmed up its gone, which is about five miles ive tested it recently start/stopping, ive taken out the rear drive shaft to check the universal joint but all is perfect, any advice greatly appreciated. Michael

I'd start by having a look at the clutch to see if it is adjusted to specs and the cable is in good nick.

The shudder on take-off disappears after about five miles of riding?

Hi I had a similar thing with k75 after I trailered it for 600 miles, I could here the drive shaft clunk when I pushed it not running but after we rode it went away. it was a new universal.

Brian

First thing I would do is check out the clutch as it is very indicitave of a worn clutch plate and pressure plate.
Check the adjustments first but I reckon you will find a worn plate or possibly the spring diaphram may be losing some tension.

whilst doing the clutch adjustment thingy .....just check that the clutch arm (back of the gearbox ) isnt tight , is free to moove .

a few folks have found this to be almost siezed .. and i just wonder if this might be a contributing factor .

Hi guys thanks for the advice well I checked the clutch cable tension I was able to take the cable off the arm at the back of the gearbox without slackening the cable, Ive tightened the cable now although not perfect the level of shudder is minimal and I can live with it thanks again. Michael

You did check the free arm operation and adjusted the clutch correctly (first 75mm at the arm, measured over the cable, and then 2-4 mm at the handle)?

Hi there, it is very important to adjust the cable as per Rene´s advise, otherwise you are risking the rubber boot´s integrity. This may cause oil leaks and contamination to the push rod mechanism.
Best regards
JAP