[amnt]

The front forks on my sons 150 seem to be sagging under the weight of the bike. To my knowledge(i bought the bike used) they have not been serviced, but when looking at the bikes profile the front seems to be sagging. I have raised the front and have noticed a little sagging. All this to ask...can I go to heavier oil to prevent this? Can I add extra oil without blowing the seals?

[nwoldnslow]

Yes!!! to all of it.

Actually it is a good time to change out the fork oil. Go get a good bottle of 10-15w synthetic fork oil and add 360 cc to each leg. If trails/woods stay to the 10wt or if GP or MX mix go to 15W. Add 5cc at a time to get to where you want. I would not go over 385 cc total. Never had a problem, however I ran seal savers.

You may also preload the springs with a stack of 1"OD stainless steel (not zinc coated) washers. Just match the stack in each leg. Start with a 1/2 " stack in each leg.

To add adjustments of either, just lift the front off of the ground and loosen the top pinch bolts. Use a good fitting socket with an extension to a socket wrench to take the caps on and off. (Can't find the torque specs at the moment however somebody should post up)

***CAUTION***

Those caps are soft. DO NOT CROSS THREAD OR OVER TIGHTEN!!!

[/i]

[amnt]

do I add the washers to the top of the fork or the bottom? Sorry, this may be a stupid question but I have not taken the forks apart and I am a little intimidated.

[nwoldnslow]

Not a dumb question at all. The CRF150 has progressive springs, so giving them some preload helps them stay up in the stroke.

When you take off the caps, you will unload the springs (untension). Add the stacks just below the caps on top of the springs. Use the socket (with extension or on a speed wrench) to push the springs down with the caps and start the threads.

Here is a great tutorial:

http://www.thumpertalk.com/forum/showthread.php?p=1940565#post1940565