Join Date: Nov 2009
Location: Lander, Wyoming
I just used compressed air pressure from a regulated air line, continuous supply, steady flow, checked pressure by airing up a tire and using a digital air gauge.
KLR style, Simple, Cheap and Easy, to quote Norm K.
MY modified relief valve, starts relieving at 22-23 PSI, Limits at 32-33 PSI.
It has a very light spring, almost 'zero' preload.
I had to compress the 'REPLACEMENT' spring in a vise, 'just slightly' and heat the end coils, several times.
I have NO WAY to measure my spring, but it is VERY LIGHT, compared to an original! Might I suggest a quarter of the original strength, squeezed between your finger and thumb.
Modify at "YOUR OWN RISK"!
Still riding my 1987 KL650-A1. 84,000+ miles & counting