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fork way too soft after oil change

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ive ridden my bike for a couple years and i felt it was time to service the fork with new oil, so i did Everything by the book.
I put the bike on a stand so the front Wheel is up, unscrewed the top caps and took out the springs and bleed the oil by removing the bottom screws.
pumped the fork up and down to get Everything out, installed the bottom screws and filled it with new oil and installed Everything and the fork is way too soft, tried adjusting the compression screws on the bottom but it changed nothing!
help please :mellow:

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What sort of bike is it..???,,at a guess I'd say 650R,,

 

How much oil did you put in each fork???,,What amount in cc or fl/oz??

 

What type of oil did you use???

 

Normally you'd just add more oil if they ended up way too soft or put in a combo of say half the light grade oil and half ATF in place of the light grade oil you're using. TBH it's probably not the best to be doing the forks while they're

still in the clamps..Bit hard to get them totally drained ,,if anything doing it the way you have I'm surprised they didn't

end up a little stiff as it's difficult to get all the oil drained with the forks in position..It works but isn't that accurate.

Edited by Horri

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forgot to mention its a xr 600 1998 an im probably the 5th owner or so, i used ATF oil (didnt say viscosity but id guess 10w.) i googled it Before and every topic said 585cc so i started with that, weird thing is that when i meassured the old fork oil it was 800cc in EACH fork! :jawdrop: 
so i Went 800cc and beyond, maybe around 850 and it still felt terrible, almost no resistance feeling and it stays 20% compressed with the bike just standing still.
what confuses me the most is that its still no change at all when screwing the compression at the hardest

EDIT: could it be clogged somewhere so the compression gets messed up? pretty much all oil ran out when i unplugged the bottom screws when checking for faults.

Edited by emilcrazy

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Don't know about the clogging..Have you the manual??,,Instructions are as follows for the after 90 bikes.

 

Pour half the recommended fork oil into the fork pipe.

 

Pour the other half into the piston rod until a little oil flows out the side breather hole at leveling minimum stroke.

 

Pump the piston rod and fork tube slowly 8-10 times.

 

Compress the fork leg fully and leave it for 5 mins to settle the oil level.

 

Measure the oil level from the top of the tube..Standard level 125mm,,(4.92in)

 

If you can understand that you're a better man than I,,(leveling minimum stroke???)

 

You're correct with the amount per leg..580cc,,19.61 fl/oz.

Edited by Horri

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You need to "bleed" the air that's trapped within the fork internals.  There won't be any damping until then.  I've always taken the forks off the bike; it would seem to be more effort to leave them in place.  There are tutorial videos on Youtube of how to bleed a fork.  It's down by manually working the internal rod up and down slowly, many many many times, until the air is eventually dislodged and can float up to the surface of the oil.

 

Just riding the bike as it is will eventually purge the air, but the suspension won't work correctly until then.

 

Also, 1998 forks get 5w fork oil generally.  The ATF is thicker viscosity and will give stiffer damping.  You may want that if you way more than the average rider weight, which I'd guess is maybe 75 Kilograms.

 

Generally the most accurate way to measure the correct amount of oil is by the height of the oil level within the fork, rather than the oil volume.  That's because not all the oil drains out.

Edited by heart_of_darkness

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And level is more critical than the amount. Too high and the seals can literally be blown out. Sounds like your springs need more preload too.

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i took the fork apart again and saw that the fork piston leaks, it was really noticable when i blew some air in it, and tried pumping it the rod with the compression screw on the hardest with almost no change from softest.  so the problem is most likely found! thanks for the help guys  :)

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