03 Busa fork fluid level

[Busman03]

Hi Folks:

I've replaced my fork seals and have a question about how much fluid to put in each fork. There seems to be a conflict of information provided by the Factory service manual and I need to get some advice.

The manual indicates a capacity of 480 ml. per fork and the measurement from the top of the fork is 3.9 inches. My dilemma is that the 3.9 inches equates to 457 ml. of fork oil, not 480. For clarity I did not disassemble the damper unit, I only accessed the top end however that shouldn't account for a 23 ml difference per fork as I drained the forks over night.

Now having said that, I understand that the all important thing is that each fork has the same amount of oil and subsequently the same amount of air. My question is, which metric should I achieve? I feel that the 3.9 inches is the correct metric. I would appreciate all advice given as I don't want to have to open the forks again.

 

[sixpack577]

There is still fluid left in the cartridges.
And, fluid level/volume can be adjusted higher or lower to change the performance of the forks.
I would not add the full amount of fluid, as there is some still in there, which may make the forks too firm
But, if you want a definite number for just a Gen1 seal change
@GIXERHP
could give you that.
He'll see this post now as he's been tagged in it.

 

[Busman03]

There is still fluid left in the cartridges.
And, fluid level/volume can be adjusted higher or lower to change the performance of the forks.
I would not add the full amount of fluid, as there is some still in there, which may make the forks too firm
But, if you want a definite number for just a Gen1 seal change
@GIXERHP
could give you that.
He'll see this post now as he's been tagged in it.

Thanks. the forks were already reassemble before my post. I just wanted to get some opinions from others who may have been in a similar situation, before putting the bodywork back on. I appreciate your input.

 

[WuzzaCBXRider]

Thanks. the forks were already reassemble before my post. I just wanted to get some opinions from others who may have been in a similar situation, before putting the bodywork back on. I appreciate your input.

Hell of an afterthought there.

 

[Busman03]

Hell of an afterthought there.

Not really, I had the levels equal and correct according to the distance from the top of the fork metric. If that is too spongy, as sixpack577 inferred then could simply remove the fork caps and add an equal, all be it very little more fluid to stiffen it up. In hind sight it is probably better to have too little fluid in the forks than too much. Adding fluid is much less labor intensive than removing fluid. This forum is quite helpful.

 

[Busman03]

There is still fluid left in the cartridges.
And, fluid level/volume can be adjusted higher or lower to change the performance of the forks.
I would not add the full amount of fluid, as there is some still in there, which may make the forks too firm
But, if you want a definite number for just a Gen1 seal change
@GIXERHP
could give you that.
He'll see this post now as he's been tagged in it.

Thanks again, your insight made me think about the problem more thoroughly. You are a credit to this forum.

 

[sixpack577]

Thanks again, your insight made me think about the problem more thoroughly. You are a credit to this forum.

Thankyou, but it's no big deal, I'm glad that I could help.

 

[bigoltool]

Racetech recommends 110mm.