fork oil changes

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11/19/2012 2:32 PM
Edited Date/Time: 11/19/2012 2:40 PM

Hey up!

When people say change the fork oil every xx hours do they mean both the inner and outer chambers? I assume so. Also how long do you guys go before fork/shock oil changes...30/40hrs?

I was planning on changing the springs and "outer" oil later this eve. I would like to change the inner cartridge while I'm there but i am a little unsure how to properly do this (burping or bleeding the cartridge) + i don't have the slotty cartridge cap tool thing.

Bike is a 2012 rmz250 with about 15hrs on it.



11/19/2012 2:53 PM


When changing fork oil on a twin chamber fork such as yours, it is best to change both oils. The inner chamber (cartridge assembly) actually mixes and shares oil with the outer chamber. This happens when your forks bottom out, as fluid is pushed passed the cartridge seal and into the cartridge. That is one of the reasons why twin chamber fork cartridges (Showa, KYB, WP, MXT E7) are designed to self regulate oil quantity.

Depending on your riding level and application 30/40 hours is a common practice.

There are many Youtube videos that show how to build and bleed your style of Showa forks. Like anything the first time will be a learning experience.

Also a 32mm socket also fits the fork cap compression assembly and can be used.


11/19/2012 3:12 PM

Thank you for the quick response.

Ok so using a 32mm socket i can remove the cartridge myself. Nice!

I've replace seals on these type of forks a few times on my old crf so am kinda comfortable taking them apart up until this stage. From what i gather i compress the rod. Fill up with oil. Decompress the rod slowly while topping up with oil as i go. Stroke the rod though a few times to release air. Top up again (how much I'm unsure). Install cap/cartridge. Tilt to around 15deg from horizontal stroking the rod at the same time bleeding out excessive oil and air from the weep holes around the top of the cap?

How much oil does the inner take? Could one do a full service on both forks with 1l of fluid?

Thanks again, and sorry for the seemingly obvious questions


11/20/2012 3:45 AM

Read your manual, there should be step by step instructions on how to preform this task. We have Yamaha's, they don't recommend using a full stroke to bleed the air out. Also good you tube video on this at Rocky Mountain atvmc.



11/20/2012 8:07 PM

Ta very much. If i had a manual then i probably wouldn't be asking


11/22/2012 9:32 AM

You should probably have two liters of oil to start for everything.