Forks wont hold air on 350X

[nicker71]

I checked the air on my forks and there was no presure, so I lifted the front up and put about 5 lbs in it. well this morning I I check it and their wasnt no pressure again. I havent check the fork fluid, I guess they have fluid in it. I just got it last week. I have heard my people talking about seal and stuff I was just wondering if they need to be completly rebuilt or if they may just need new seals? the front end will squat about 1-2 inches with its own weight just sitting there, but I dont have a problem with it bottoming out when I out ridding either. does everyones else's 350X squat with it own weight or is something wrong. what should I do? I dont have a book yet but Im looking for one. sounds like it not to hard to rebuild them.
thanks

[FullBore]

I don't think they're supposed to hold air, I know on an MX'er that you're supposed to let the air out after jumping.

Nat

[TimSr]

Normal pressure it atmospere, though it should be able to "hold pressure". However if they are leaking air, they should leak oil as well. If they arent leaking oil, I wouldnt worry about whether they hold air. I would change the fork oil, so you know it has good oil of the proper type and amount. Fork oil also contains seal swelling agents to help prevent leaking. If you decide you need the extra travel, and need to get rid of the inital sag, you use preload, which on forks is done by adding a spacer anywhere form an inch to a couple, depending on wht is needed, above the spring, under the fork caps. PVC works well.

[Dynofox]

Hey Tim, to add spacers to my Z forks can I just let the air out of them take the caps off and toss them in?

[Dynofox]

Also what diameter would you recommend?

[Yamaha_Rules69]

Tim SR, does putting pvc pipe in really help out? In what ways? Thanx, im thinking about doing it on my 200x. )

[Dirtcrasher]

As long as the outside diameter of the PVC is about the same as the spring you'll be ok. You don't want it to get hung up in there either on the inner fork tube wall or the spring. The ends must be cut relatively square or sanded on a disc to 90 degrees. Then just expirement with the length till you get the desired spring action.

Never done it but I assume thats how it's done.

[TimSr]

Yep, what DC said.

Keep in mind, this is an adjustment. This sets preload, just like that big locking nut on your rear shock. It will not necessarily make anything better, and could make it worse if its not right for you. It will stiffen things up, which helps if you are bottoming out, but will give you nothing but a harder ride, if you dont need it. If a couple inches of preload doesnt fix bottoming for you, you need heavier springs, or better yet progressive rate springs.

To install, you elevate the front so that the forks are fully extended with no weight on them, and simply take the caps off, and put them on top of the washer on the top of the springs. You will then have to put the caps on top, and force them down, while tightening them at the same time, so be careful not to cross thread.

[Yamaha_Rules69]

One last question, sorry about bringing this topic back to the top. ? I was wondering if the pvc pipe would break. You would think that it would, because of all the pressure being put on it. If it did break, it wouldnt be too good. It would probly wreck the springs and damage the inside of the fork tube. How have they worked out for you? (those who have tried it) What are the chances of it breaking? Thanx again.

[Jeb]

The PVC pipe will not break but if you're that worried about it get some aluminum tubing. It can easily be cut with a hacksaw. As said before, the trick is to get a size that just slips into the fork tube and cut the ends square. Back in the day, I always stiffened up the front end of my dirtbikes this way. If you go too long with your pre-load spacer it may be tough to get the fork cap thread started.

Good luck and let us know what you think when you do it!

[MR ATC]

ive had the same pvc spacers in my 85 350X for 17yrs with no problems at all the pvc will hold up.

[Truckster]

Are the air valves themselves leaking. I think others were thinking of the fork seals leaking...

change the valves themselves, and see if it changes it.

Some older bikes had air assisted forks, but as someone else said, should let it out of most.

[TimSr]

The aftermarket progressive springs I bought were shipped with PVC spacers included.