If you dismantle the kick lever from the splined boss by removing the circlip on the top and withdraw the lever (carefully as there should be a spring and two ball bearings inside) you can replace the stuffed spring or install one where there was previously none by the sounds of things. The spring is a tight little sucker and if you dont have one, or need to replace the one you have, try trimming down a spring from the gear selector detent lock (found in the sump plug of most RM's of that vintage) and grab some ball bearings (qty-2) from your local CBC or what have you. Fit one bearing at each end of the spring so that each ball extends past the post on the boss by approx half the ball diametre, installing the assy is tricky, but this will save a costly replacement. While you are at it, check the swing on the lever (from stowed to extended) and see if you wouldn't benefit from adding a small bead of weld to the boss that you can file back to re-align the swing so that your lever is no longer bashing in your cooling fins or swung back too far when you are starting
hope this helps
