Fork oil capacity

[bdfinally]

OK, I'm jerking the non-adjustable Marzocchis off my '00 M750 today and refreshing the oil and putting in new Racetech springs. Got all my how to threads bookmarked, but I need to pick some brains. Haynes manual says the oil leve is 90mm (3.5 inches.) It also says capacity is 380cc (12.8 ou.)

So just pour about 15 ounces in and them draw it out til I reach 3.5 inches from the top? I'm using a cheap Progressive Suspension oil level kit.

The other question is about the washers sent with springs. There are 4 each of two different sizes. No spacer material was included so I'm assuming that they determined none was need for my model. Once I take the fork apart to drain will everything just be evident about where to place these wasshers or is there some other measurement I need to take into account?

Thanks in advance.

[battlecry]

If you have the time, let me suggest that you assemble and install the forks without the fluid.  Then measure the sag and see if it is within range.  If not, you can probably call RT and ask them for the proper preload spacer length your your spring rate.  You can make it yourself out of aluminum tube or pvc pipe, or you may be able to order one from them.   You may need a spacer, even if none was included.

While you have them on the phone, ask them for their take on the oil level, it may be different than the Haynes manual.  

Measure oil height with the springs out, and the fork vertical with the stanchion compressed.  Be sure to pump the rod a few times and bleed all the air out of the damper before measuring the oil level.

Don't know why you would need 8 washers, maybe they sent you extras to fit different diameter springs or accommodate a spacer.

[bdfinally]

Thanks for the suggestion, but I think I'll set sag in a week or two when I deal with the shock too. I need to get this buttoned up today or tomorrow at lastest, we may be getting another snowpocalypse

13.8 ounces came out of one fork, which is 1 ounce more than haynes calls for.

the other thing I found was



old progressive on the left, new one on the right..should there be that big a difference in length?

[Speeddog]

You're going to need a spacer.

Best place to start is with the length of the new spring + spacer = length of OEM spring.

You can use pvc pipe for a spacer.

[bdfinally]

 Thanks SD, looks like the difference in spring lengths is 3.25 inches. Washers that came with are either 1 1/4 or 1 7/16. I'll see if Lowes' has some 1.25 PVC.

so the order back into the fork would be first the spring, then spacer with washers on each end and then sleeve or spacer at top?

[ducatiz]

Thanks SD, looks like the difference in spring lengths is 3.25 inches. Washers that came with are either 1 1/4 or 1 7/16. I'll see if Lowes' has some 1.25 PVC.

so the order back into the fork would be first the spring, then spacer with washers on each end and then sleeve or spacer at top?

I assume the whole thing will be under tension so the washers will stay in place.  I wonder if you can run something thru the washers and pipe to hold them together as a unit.

Pretty good idea to use PVC as a spacer.  What type? Sched 40, Sched 80 or the PVCO/MOPC (molecularly-oriented polyvinyl chloride)?

[ducpainter]

I assume the whole thing will be under tension so the washers will stay in place.  I wonder if you can run something thru the washers and pipe to hold them together as a unit.

Pretty good idea to use PVC as a spacer.  What type? Sched 40, Sched 80 or the PVCO/MOPC (molecularly-oriented polyvinyl chloride)?

The damper rod runs through and attaches to the cap.

[Speeddog]

As far as which size of PVC pipe, OD of whatever's closest to the OD of the spring, ideally just small enough to fit into the fork tube.

ID closest to the ID of the spring, as long as it'll fit over the damper tube, and over the little plastic cup gizmo that's on the damper rod (if so equipped, Showas have 'em, not sure about that vintage of Marzocchi).

You'll need to lower the fork oil level to account for the volume of the spacer.

[bdfinally]

This what it looks like with the fork pushed down, spring sleeve the retaining clip and nut on the damping rod



this is what I've rigged up and in order (?) to go back in



What do you think guys?

[bdfinally]

I think I'm at a stopping point. In putting the new spring in the fork I noticed they didn't fall as far into them as the old ones did, so I measured them up and found that the RT springs OD is about 3/16 smaller than the original and the ID is about 2/16 smaller. I've checked my order and invoice and the part number is the same as what Race Tech says is good for both the "00 M750 and '00 M750 dark. Anyone think it time to pull the dampening rod out and see whats up or should I just wait and talk to RT on Monday?

edit to add: I think I've found the problem. Both the Race Tech site and the Haynes manual list the forks as Marchozzi 40 U...mine are Showa GD051-50.

[scott_araujo]

Yup, that's probably your problem.  A few notes...

I bet RT will exchange the springs for the ones you need.  They're a good company.  Ask them for spacer material when you order the new ones.  When I did my Marzocchis I asked for lots of spacer material and they sent me a 2' piece of aluminum tubing that was the perfect size, no extra charge.

Forget volume, go by oil height.  Whether you use Hayes setting, what RT recommends, or something else go by height.  Remember to set it with the fork tube fully compressed and everything except the spring installed.  Make sure you pump the cartridge when draining to get all the oil out and pump it again when filling to get all the air out.

Scott