Rear Shock Troubles!!!!

Rear shocks do not determine the sag. That is controlled by the rear spring and the compression adjustment on the spring. Adjust the tension on the rear by the collars around the shock and see if you can get the sag correct. It may be that you need a new spring of a different strength. Check the bearings in your bottom shock linkage, they may be gone and giving you a false sag. Ride safe John

Do you know if it has the stock spring? The stock spring is sky blue. If it is sky blue, then there's a great chance it is the stock spring instead of an early 1990's KX spring.

If it is the stock spring, then you MUST get a stiffer spring, as the stock spring is not designed for someone of your weight. Adjusting the preload collars WILL NOT make up the difference. That is NOT what they are designed to do.

Your bike IS 5 years old and MAY need a rebuild on the shock, but unless the linkage is sticking, that won't affect JUST the sag. You need to first get the correct rate spring for your weight (weight in full riding gear, not just YOUR weight). After you get the correct rate spring, THEN you can use the preload adjusting collars to fine tune the sag.

Don't forget the front suspension as well. You need the correct rate springs front and back to keep the suspension balanced.

www.mx-tech.com has a good spring rate calculator. Stock rear spring is 5.0 Kg/mm rate. You may need a 5.5 or 5.6, depending on your weight in riding gear.

www.racetech.com has a spring rate calculator and an article on how to measure sag.

Once you get the springs and have the sag correct, it will be a night and day difference to you.