changing fork oil

I want to change the fork oil and can't see any info on this topic.

Do i just loosen the fork tops,remove fork and drain out old oil and refill?

Do i need to flush out the old oil with some new oil?

Whats a common grade of oil for riding trails/bush?


It is just about impossible to get all the crud out by just dumping the oil and refilling. Removal, disassembly and cleaning is the best way. If you can't disassemble, dump the oil out, pour in some clean oil, pump the forks a few times, dump it out. It could take several flushes before the oil comes out reasonably clean. The service manual says to use "suspension oil 01" whatever the hell that is. I use Belray 7 wt. fork oil in my '00 WR400, never had a problem. Standard oil level is 135mm from the top of the tube with the spring out and the fork collapsed. You can adjust the level about 10mm either way to change the damping.

The service manual says to use "suspension oil 01" whatever the hell that is.

Suspension oil 01 is Kayaba 01 fork oil. Enzo Racing imports it from Japan and sells it here in the states.

Here's some posts with info on Kayaba 01 fork oil:

The Yamaha owner's service manual has a very good description of the fill and bleed procedure for the front fork. You can download a free copy of the manual in pdf format here:

I just went through this. Enzo sells the 01 oil for less than Yamaha. it feels pretty thin (which should mean nothing)

A quality Motorcycle fork oil in 5wt would be the next closest thing.

The manual is a great place to start for fork oil level reccomendations.

My forks are set up for 5wt at 120mm. My forks have been revalved and utilize this set up. the tuning section in the back of your manual will describe the affect of different fork oil levels will have on fork performance.

That Enzo oil is the Genuine Oil from Kayaba

You are going to need two (2) liters maybe three(3) liters if you need to to alot of flushing.

Good luck and don't worry the forks are not that complicated once you get in there. Just make sure you check the lower fork slider tubes for "Dings" and sand them down with 600 grit or a stone. Now would also be a great time to install new fork seals and dust wipers.:applause:

had anyone seen the recent dirt rider mag? page 125 march 2008, called "Fork Height Equality" ..... and just how about does he do this? there's just no detail .......

I've had to do the "film trick" several times because of the sand I ride in, and guessed at adding oil to even things up ....

today my "Progressive Suspension, Pro Fork Oil Level Kit" (DennisKirk Part# 28409) should come in today, and maybe that will help out.

anyone use this?;jsessionid=3P5QHKPVNZJKJLA0WTKSM4VMDK0NCIV0?store=null&skuId=28409

kool name

mine is marty behan

I just changed my fork oil with bel-ray 5wt for the 3rd time with no problems we ride allot of rocky mountains and need soft forks! Go with the Yamaha service book and it will take you about 45 min to completely rebuild the shocks!!

Thanks for all your replys and the links.I did look in the manual but it says nothing about just changing the oil. I too was wondering what oil "01" was?

Looks like i'm going to be stripping some forks!

Thanks marty, Behan is an Irish name,i suppose you know that anyway and

as the coats of arms say...There is no motto for the Behan's.

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