I have a 86 250R and was wondering how to make the rear shock stiffer. I tried screwing the spring down but it didnt seem to help, what do I do?

 

By screwing the spring down, you are changing your preload or "race sag". To make the shock a little more stiff, turn the compression **** on the canister clockwise. To adjust rebound, adjust the screw on the bottom of the shock. This will adjust how fast the shock will return to its normal position. If too fast, the seat will spring up and launch you off the seat. If too slow, you will not use up all the suspension because the shock will not be able to return to its normal position before you hit the next bump.
Race sag should be 1/3 (I think)of your normal ride height(you not on the bike).
ERIC

 

You may need to have the shock serviced for Nitrogen pressure. Just had one done for a 250R & it was 80 lbs low on pressure. Not all bike shops keep the nitrogen tanks around. Actually did mine at an aircraft service facility (they use nitrogen in the struts and tires).

 

Actually, what were suggested were all cheap temporary fixes. They will not last long at all. What you need is just a general service of the shock. Oil change, new seal, fresh nitrogen charge etc. This will probably cost about $80-$100 but it will help dramatically. If I were you, I would just send the shock to TCS and get a complete rebuild/revalve. When you get it back you won't believe the difference.