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Fork oil change

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It is time for a fork oil change. When you look at the honda manual description of how to do it I get the impression that one needs to be a rocket scientist. Reading Shawn Mc's fork seal replacement thread it looks almost too easy. Whats up with that? Any one got any helpful hints?

I fear starting another oils war but must ask: Shawn runs synthetic atf. Whats best oil or atf. I would really like to hear from the heavy hitters like Kelstr and RHC. Thanks guys.

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I was just researching the same thing. Try a search for "fork oil" there is TON of info already on here.

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Do not use power tools at all if you are doing it yourself. Apend a little on the proper tools unless you are crafty enough to make your own.

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You don't need to take the fork completely apart to change the fork oil.

Steps:

1. Remove the forks from the triple clamps (loosen the fork damper cap before you remove the fork).

2. Unscrew the fork damper cap and turn the fork upside down.

3. Let the fork drain for about 1 hour.

4. Add 371.5 cc of oil (about 3.5 cc of oil remain in the fork tube).

5. Reassemble and install.

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what about the inner chamber? Thats not enough oil for both, right?

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correct 375cc is only for the lower leg of the fork. the inner chamber is sealed unit all by itself located on the top of the fork. i usly run 198- 200cc in the upper chamber you cant'as far as i know put to much in the upper chamber because when you are stroking the dampner rod to get the air out it will come out of the bleed hole on the out side of the cartrige, i usally do this while the fork is diassembled and i don't have to worry about that going into the lower fork leg. while bleeding the dampner rod the excess will come out just don't let it get into the lower leg, i just leave a rag on the floor and the end of the dampner rod on that so it doesn't mess up the threads on the end of the dampner rod.

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You don't need to take the fork completely apart to change the fork oil.

Steps:

1. Remove the forks from the triple clamps (loosen the fork damper cap before you remove the fork).

2. Unscrew the fork damper cap and turn the fork upside down.

3. Let the fork drain for about 1 hour.

4. Add 371.5 cc of oil (about 3.5 cc of oil remain in the fork tube).

5. Reassemble and install.

According to the manual I think 3.5 cc is what remains when you disassemble the fork. When just draining and replacing the fork fluid like you mention 7cc is what's left.

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You don't need to take the fork completely apart to change the fork oil.

Steps:

1. Remove the forks from the triple clamps (loosen the fork damper cap before you remove the fork).

2. Unscrew the fork damper cap and turn the fork upside down.

3. Let the fork drain for about 1 hour.

4. Add 371.5 cc of oil (about 3.5 cc of oil remain in the fork tube).

5. Reassemble and install.

while this is correct. i find it much easier to loosen the top clamp and then pop the fork cap loose. the top triple clamp kind of squeezes the fork tube cap tight. :thumbsup:

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According to the manual I think 3.5 cc is what remains when you disassemble the fork. When just draining and replacing the fork fluid like you mention 7cc is what's left.

the amount left depends on time spent draining.. i think it said something like 12cc's for only 20 min. so for an hour he might be correct

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what about the inner chamber? Thats not enough oil for both, right?

When the fork action starts to suck its because the fork oil is sheared all to hell and out of spec. All that action takes place in the inner chambers. You could feasably change only the inner oil and restore the proper action. The oil in the outer chambers is only there for lubrication and setting the bottoming resistance with the level.

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Shawn,

I admittedly don't know dick about suspension. My YZ is stiff on the initial stroke over the smaller bumps but feels great on the jumps and has great bottoming resistance. Can I do something myself to smooth out the small stuff without having to back the compression off thereby killing my bottoming resistance?

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Shawn,

I admittedly don't know dick about suspension. My YZ is stiff on the initial stroke over the smaller bumps but feels great on the jumps and has great bottoming resistance. Can I do something myself to smooth out the small stuff without having to back the compression off thereby killing my bottoming resistance?

You can try to split the difference with the outer chamber oil level. I dont remember what the outer level is, but you could try dropping the level about 10-15cc's and see how it works. Hopefully you dont give up too much bottoming resistance, if any...

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What about atf vs fork oil? Shawn, I believe you said in your thread that you use atf. Could you notice any difference with atf?

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I just did this on my 450x last weekend. Its the same steps.

I did not dissassemble the lower leg at all and followed the rest of the manual directions.

I had all day and didn't want to deal with the "how much didn't drain" so I jsut left em draining for about 2 1/2 hours while I ate dinner and had a beer or 2,

Put 190cc in the inner, pumped it like the manual said and 17cc drained out just like the manual says. (this was really the only step that worried me with not dissasembling the lower)

I went up on the outer cc to 375 because I wanted firmer action closer to max compression.

It's time consuming but not really hard. next time it will take less than half the time I'm sure.

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