125-200cc Fork oil change/ lost rebound dampIng

I have a set of 45mm zocchis. I've changed the suspension fluid on my previous husky. Same fork.

But now it seems like I'm not filling the damping rod properly. I fully compress the sliders, fill the damper rod fully and fork chamber most of the way. Then put my finger over the damper rod and cycle it to fill the damper cartridge.

With it full after repeating this I put the inner damper rod back in(fork still compressed). Then finishing topping up the fork. Reassemble.

I've done this twice now and followed the service manual very closely. I can't think of anything I could be doing wrong.

The service manual is for an 04 husky, I have an 08 but the forks appear identical.

Did you have a loss of rebound before the change which maybe prompted this service? Either way, a loss of rebound could be explained by a problem with the mid-valve stack, or the checkplate if there is no midvalve. To check it you need to remove the cartridge, spin the nut off the top, wrap the threads in teflon tape, and push it from the cartidge. The rebound stack ( against the nut) could have debris trapped in it, or the float in the midvalve could have bound and prevent it from clamping to the piston, or perhaps the spring/checkplate has an issue. ive seen a checkplate start threading itself down a spring effectively eliminating any rebound control.

Ok guess I'll have to dig a bit deeper into the fork.

Really confusing, no issues before oil change. Only removed springs, preload spacers and top caps.

And both fork legs have the same issue. I tried a 3rd time re doing a fork leg. No dice. Frustrating

I'm using 5 wt oil. But really doubt that would be the problem. As is the fork tops out like a pogo stick.

OK then maybe cartridge isn't filling. Add oil. Ignore cartridge, raise outer tube, clamp hand over it and compress, using trapped air to force oil into cartridge. you should be able to work the cartridge rod and feel the air bleeding. Don't clamp finder over the rod, let oil flow.

Gave it a shot but no luck with that method either.

Thanks I really appreciate your help though.

Think ill check out the lower internals tommorow.

Well pulled both fork legs apart. checked shim stack, check plates clear of debris moving freely.

Refilled everything again. Still absolutely no rebound dampening. At my wits end.

I just can't fathom what's wrong. Maybe I shouldve tried running 10w to see if that makes a difference.

Might have to take it in to a suspension shop. Sheesh what a can of worms for a routine fluid change

Having both forks go at the same time sounds a little weird also ...

Is the 5WT oil the same as you have used before in your forks?

--

I did read an article once where some valving on a specific fork needed 7.5 WT and above oil or it would not work properly because some of the holes in the valves needed that oil weight or it just passed through some of the valves and provided no dampening ...

Might be worth a shot to try one leg with heavier oil before you reach for your wallet ...

Same thing happened to me, no oil in the cartridge. 5wt oil is fine you just need a way to get oil into the cartridges; I used a syringe it takes awhile with this method.

I'll be doing this same fluid change on my 45mm zocchis also on the near future ...

Feel free to post a few pics ...

Finally!!

After trying to re fill/ bleed the damper rod from the top for 30min.

I removed the whole cartridge again. Inverted it with the rebound rod in. Filled while cycling the rod. Reassemble. Super easy and fast. I found the idea through this link.

http://www.dirtrider.net/forums3/text/topic/133279-1.html

I strongly suggest anyone use this method. Coulda saved me hrs of frustration.

Thanks for all the help guys. Stoked I can actually ride today

http://www.scottysdirtbikespares.com/workshop-help/gas-gas-fork-service.html

There's pictures. You don't have to separate the fork legs of course. The rest is pretty self explanatory

Very odd! I've never had that happen and have done scads of them, as well as mid-90's KYB's practically the same. The old hand over the female leg and compress works every time. Anyway glad you got it handled!

Bahaha! I can't believe I missed that set-up! Nice K I'm a dirty old man but you, sir......