First oil change in my Marzocchi forks!

[Phatpat]

..seen your mx video, looked light

Just let us know what brands you can source and then we can advise.
You are looking for SAE 7.5W (in general) and with an actual viscosity between 23 to 26 cSt.

Haha ok, and here I'm sat thinking that Gopro was facing forward and not on me!? But yeah, I'm about 73-75 kg, all muscle!

Well I've got quite a few local dealers so I'm sure I can find whatever is needed. Without having to read the manual, is that what I use for the outer chamber too?

[stillwellperformance]

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We use this procedure in the shop, it's accurate and quick to do. It also allows you to install the compression assembly without tearing a rotor cuff lol.

I can't stress enough how important it is to take your time when bleeding the inner cartridge. Once you have oil in the cartridge, (enough to fill within 30-40mm of the upper bleed hole) stroke the cartridge rod down firmly-then stop. The first couple of times you will probably hear air moving as it looks for the top. Give the cartridge 10-15 seconds to let air bubbles rise, then SLOWLY raise the cartridge rod all the way up. Stroke it down again firmly-stop, wait a bit then repeat. You are allowing the bubbles to find the top. Continue this until you feel firm, smooth action both ways.

Now, once you are sure the air is out (you will feel damping both directions) pull the excess oil out of the cartridge with your suction tool. You want the oil height to end up 140mm from the top of the tube. This ensures you have excess oil to bleed off, and also allows the compression assembly to be re-installed with the minimum amount of effort.

We use suspension vises here at the shop, I saw some other good ideas for holding the cartridge in this thread as well. Stand on a bike stand if you need to, but get directly above the cartridge. A little anti seize on the comp assembly threads works wonders, push the assembly into the cartridge with the flat palm of your hand (if you have a shop towel over the assembly, make sure it does not find its way into the threads as you push down).

As you are pushing the assembly down spin your palm until the threads catch, then tighten. It's easier said than done, but standing above the cartridge helps us a bunch. Sometimes it takes a few tries!

After you tighten the assembly, put the completed cartridge over a drain and compress the rod completely. You will have a small quantity of oil expel through the bleed hole. The cartridge is now ready to install.

I liked the "some of the factory studs are running 380cc" comment, we in fact run anywhere from 330cc to 410, depending on the rider and the race we are tuning for. EnduroCross needs a high level, National Enduro's and Extreme races like the Tennessee Knockout take less. I would not advise anything less than 300cc.

Like always, test, test test. (It's easier to start with a higher oil level, then drop it 10cc at a time until you find the best height for your application).

Hope this helped, Keep It Pinned!

Alan
@tunerdude
@stillwellperformance

[Jakobi]

We use this procedure in the shop, it's accurate and quick to do. It also allows you to install the compression assembly without tearing a rotor cuff lol.

I can't stress enough how important it is to take your time when bleeding the inner cartridge. Once you have oil in the cartridge, (enough to fill within 30-40mm of the upper bleed hole) stroke the cartridge rod down firmly-then stop. The first couple of times you will probably hear air moving as it looks for the top. Give the cartridge 10-15 seconds to let air bubbles rise, then SLOWLY raise the cartridge rod all the way up. Stroke it down again firmly-stop, wait a bit then repeat. You are allowing the bubbles to find the top. Continue this until you feel firm, smooth action both ways.

Now, once you are sure the air is out (you will feel damping both directions) pull the excess oil out of the cartridge with your suction tool. You want the oil height to end up 140mm from the top of the tube. This ensures you have excess oil to bleed off, and also allows the compression assembly to be re-installed with the minimum amount of effort.

We use suspension vises here at the shop, I saw some other good ideas for holding the cartridge in this thread as well. Stand on a bike stand if you need to, but get directly above the cartridge. A little anti seize on the comp assembly threads works wonders, push the assembly into the cartridge with the flat palm of your hand (if you have a shop towel over the assembly, make sure it does not find its way into the threads as you push down).

As you are pushing the assembly down spin your palm until the threads catch, then tighten. It's easier said than done, but standing above the cartridge helps us a bunch. Sometimes it takes a few tries!

After you tighten the assembly, put the completed cartridge over a drain and compress the rod completely. You will have a small quantity of oil expel through the bleed hole. The cartridge is now ready to install.

I liked the "some of the factory studs are running 380cc" comment, we in fact run anywhere from 330cc to 410, depending on the rider and the race we are tuning for. EnduroCross needs a high level, National Enduro's and Extreme races like the Tennessee Knockout take less. I would not advise anything less than 300cc.

Like always, test, test test. (It's easier to start with a higher oil level, then drop it 10cc at a time until you find the best height for your application).

Hope this helped, Keep It Pinned!

Alan
@tunerdude
@stillwellperformance

It won't be fully bled Alan.

I've spent much time playing with a set from a Gasser, and a quick and crude test is to invert the cartridge and cycle the damping rod. If there's air in there its evident immediately as you hear it being slurrped past the piston, which imo undoes all the time you spent trying to bleed it in the first place.

My method works off 225ml of oil neat. Leaves enough to bleed up, isn't too hard to install the base valve, and most importantly, allows multiple small purges.

The shape of the piston and the way it purges excess fluid (through the center) means that even if the cart is entirely upright, an air bubble will form where it vents, but it will also trap air around the outer edge where the piston is stepped.

Once assembled I turn the cart upside down for a bit, allowing the air to move back towards the piston. Without cycling the damping rod I then flip it up the right way and give it time for the bubble to come up and center. Slowly depress the damper rod until a purge is heard, and then release. Turn it upside down and drain the small quantity of oil. Repeat. You should get about 3-4 solid purges from the cart, and if all went to plan, it should pass the turn it upside down and cycle test.

The other thing I've noticed, is that these forks circulate and self purge while riding, so one could really question if its worth while doing the above.

[dirtbird]

Jacobi the bleed holes are located quite high, therefore if you just put 230ml assemble the BV and perform the assembled bleeding of the cartridge, still you will have more than the desired 210ml/14cm of oil inside, at least this is what I have found out.
I believe this is because the speed of compressing the cartridge has an effect as well. When doing by hand, the piston doesn't go very high in the cartridge. Also the damping force is not very high. Another thing I have noticed is that you can tell the slow from the fast rider by the time needed for the forks to get harsh.

The slow and light weighted riders, need 10 hrs while the faster and heavier ones can go over 30. The very fast ones, just need an oil change at 30 hrs.
This is because, slower riders, are not using all the available travel frequently and at the same time there is oil from the outer chamber entering the inner and hence increasing cartridge pressure and damping force. The latter is confirmed with Marzocchi through Beta. So, for this reason I tend to believe that for the average and on the budget, rider might be better to use a lighter viscosity oil on the outer as this might offset a bit the above and give some extra riding time between overhauls. I've tried this only once (used SAE 5W on the outer) with a very troublesome rider. He was very happy with the fork for 20 hrs of riding (first time after 2 years) but then he sold the bike and I have not more feedback.

Back to the bleeding procedure, I do it as Alan but then I leave the cartridges open and fully extended for 15-20 minutes to get an extra gravity bleeding.
Most times I almost eliminate the 'hiss' sound you describe and I can see few (2-3) bubbles coming up.

Having said all that, next time I will try your 'upside down' method to see if I can make it work.

[Jakobi]

The holes on the cartridge body aren't bleed holes. They are simply drainage holes. The only way oil passes from the cartridge past the piston is through the center as it reaches the recess/taper on the rod that runs down the middle of the PFP spring. Only one way.

I've inspected work that a renouned Aussie tuner does, and one of his mods is to recess this a touch more effectively allowing a greater volume of air/oil to purge as the piston reaches this position, which I believe is aimed at resolving the issue you posted above, regarding pressure build up not being purged off effectively during use.

I've a very intimate relationship with my Marzocchis.. Know them inside out and then some. Unfortunately, they are also showing extreme contamination and wear in one cartridge, believed to be caused by some swarf from a spring guide vs preload circlip. They're in the process of being replaced by KYB SSS, and in the meantime I'm running TTX carts in Sachs legs.

If you don't believe me.. next time you bleed a set up, invert it and cycle. It'll cost you nothing.

[GMP]

Jake and I have talked about this and I have verified that the cartridge does trap some air. He is also right in thinking it really does not matter much. When oil is exchanged, who is to say its nice clean oil? More likely all frothed up. That said, the fix for this lies in the piston design. I'd make it conical on the bottom, with bleed passages to the center area below the seal. Also reduce the min PFP preload so it's usable by mortals, and cut lands that use a bushing you can get without buying a $150 kit.

As far as bleed its been beaten to death. I do the standard method but I use a +5mm oil level for a higher pressure. I have also added PFP preload, up to 5 turns, pre bleed. This gives a very hard positive bleed, and trapped bubble size will be smaller.

As far as the oil exchange being different for different riders, not sure I buy into that. First, I ride mainly technical woods, and racing rarely bottoms the fork, almost never. When I break these down the cartridges are not over filled and do not purge on bottoming them on the bench. All is normal as far as feel and PFP piston position as seen through the drain hole. The majority of oil exchange comes from the high pressure on the damper rod seal when the oil lock enters the bottoming cone. It is clear that oil is being exchanged in the forks I maintain even during intervals of technical woods riding with no big hits.

I like the way these forks perform, but I'm not impressed with the parts distribution and pricing, and the high incidence of premature wear. I think for the $$ things could be a lot better. JMO.

[GMP]

Finished a set of GG 48s today. Anodizing was good, PFP bushings scuffed from burrs on inside of cartridge drain holes. Second set I have seen this(my GG was first). Anyway here are a few pics. Sorry no video as it's a two handed job. If you don't get it then quit now.

First is a seal driver fit around the cartridge. I have both 45 and 48mm, both work. I used the 45 as I was doing seals while the cartridges were settling after filling and pre bleed.

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Here is the setup in a basic vise. Very easy to work with. The compression cap tool is home brew.

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Here is what happened to the PFP bushings from burred drain holes. During assembly when the unit is pushed and manhandled past the holes. Once assembled the bushing does not ride on this surface.

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[dirtbird]

The holes on the cartridge body aren't bleed holes. They are simply drainage holes. The only way oil passes from the cartridge past the piston is through the center as it reaches the recess/taper on the rod that runs down the middle of the PFP spring. Only one way.
....

If you don't believe me.. next time you bleed a set up, invert it and cycle. It'll cost you nothing.

Yes, not correct term. I meant the holes that are disposing the excess (?) oil.
Glen uses +5mm oil level so this show that only when the oil volume gets significantly more, some of it will exit through the cartridge holes.
One fix might be to open new draining holes slightly lower in the cartridge.
As I said, next time I'll use your bleeding technique as well.

Glen, on most sets I serviced last year, I was using the Beta Racing team oil quantities (370ml for 4 str. and 380 ml for 2 str.).
Perhaps this explains my findings......

[GMP]

380cc outer oil would be brutal! For my 180lbs and speed the fork is firm enough in the later travel with 300-310cc. I have only bottomed on an MX track.

[stillwellperformance]

Actually the fork is completely bled. You need to do the procedure we outlined above as you want all the air out of the cartridge before you set the oil height in it. If you do, then the oil height is set and the cartridge install goes in relatively smoothly.

We use this procedure on all of the Factory Beta/Stillwell Performance race team bikes for the past 2 seasons with perfect results. No need to turn the cartridge upside down.

And by purging the excess oil from the cartridge prior to re-installing it then does not affect the outer oil height.