I had one of those forks, it's really simple but still pretty nice.

Both air valves are for air preload- add a little air if you want it stiffer, remove a little to make it less stiff. You can run 0 psi if you want.

Oil volumes are right here: Tenneco Marzocchi Suspension . I had a lot of fun playing with this- you can adjust oil volume and weight to suit your preferences if you want to.

Seals are the rubber rings around the stanchions that keep the oil in and dust out, while bushings are inside the lower legs and keep the fork moving straight up and down. If your fork is not leaking oil, you probably don't need seals. Bushings need replacing when the stanchions are loose in the lower legs. Normally an old fork just needs seals.

Usually unless they are abused Marzocchi forks from that era last almost forever! They are easy to work on too. Good luck and have fun!

 

Wow, first off : THANKS FOR YOUR PERFECT ANSWER ! Answered everything, clear as can be, direct links added, AMAZING !

As you've told me you used to own one, I have a few extra questions :

Just to be sure, about the air pressure, I need to put the exact same pressure in both legs right ? Also, do you know which values I should follow (even a rough range would do) ? Because Marzocchi's user is giving positive air pressure default values, but depending if the fork is using air or spring, the values go from 0-1 bar to 4.5 bar ... which is a pretty big difference !

Also, I've been struggling to find a working adaptater to be able to set the air pressure myself (I think I'm coming close to the limit of the kindness of the mechanic at my nearby bike shop). I'm pretty sure it's a schrader valve, but some people kept telling me that I needed an adaptater, which I ended up ordering ... to discover it didn't fit ! I have a regular tire pump, which would work on a schrader, but the pump's end shape makes it not possible for it to reach the fork valve.

I've also heard that forks were using very different pressure that tires, so that I would need a specific pump ... but then I've been told that Marzocchi's ones needed much smaller pressure, so that I needed a specific Marzocchi fork low pressure pump. Now I'm a bit lost on what I actually need, could you enlighten me a bit on this ?

Just a final one : I can't bottom the fork out. If I'm correct it's a 130mm travel, and I rarely go over 100mm, even when landing after a jump (not a 10 ft drop but still .. ). Could this be because of an excessive amount of oil in the legs ? Because I've also seen that Marzocchi seemed to overestimate the oil volume to put in each legs. In your experience, especially since you had this model of fork, have you found this to be accurate or not ?

Thanks in advance for your help, believe me it's much appreciated !

And great news on the long lasting of this fork, this is one of the reason I went for this one, but really glad to have a confirmation

 

Glad to help. 2004 was my favorite year for bike gear, especially Marzocchi

for the air pressure- the numbers don't even matter, you can just count how many pumps you put in. Put in enough to reach correct sag- usually 20-30%. If it feels good, that's the right amount. I would put the same in each side. I weigh 150lbs and if I remember right I only put in 4 or 5 pumps, like 8psi or so, and usually I ran it at zero. I used a stiffer than normal spring also.

You need a high-pressure shock pump, you can't use a regular pump. Some Marz forks needed a weird little adaptor as well as a shock pump: Marzocchi Suspension Adapter > Accessories > Inflation > Shock Pumps | Jenson USA
Did you get this one? I can't remember if the Drop Off needs one or not.

Unable to bottom out could be too much oil, too much air, could be too stiff of a spring, or the travel could be set for less than you think it is. Hard to be sure without pulling it apart. I can't think of a way to be sure without opening it. Does it get really hard to push down, or does it actually totally stop moving at a certain point?

 

Thanks for these explanations !

I actually did get an adaptater, but one of these : SKS Marzocchi Adaptor | Chain Reaction Cycles ( look pretty similar but not sure ), and it didn't fit, was just a bit too large.

I'll try to post a picture of the air valve if I can find/make one.

As for the bottoming, I'd say it's getting hard to push rather than suddenly stopping, but hard to say, usually when I use it this far, I'm not looking at the fork

I'll look a bit more on my next ride and keep you posted, and I'll probably open it up when I get the correct tools pretty soon to make an oil change, not sure if the previous owner did it very often .. or at all ..

Thanks for your help, will keep you posted.

Max.

 

I currently have a 2005 AM 1 and previously had a 2003 Z1 FR SL (bought both forks 2nd hand). The adapter I use is like the one in the link Norton provided. The one you bought is specific for an SKS shock pump as stated in the ad.

I was a bit apprehensive about servicing the AM 1 but I found an online guide from a guy who owned the same fork and it turned out to be pretty straightforward.

Old Zokes are good forks. Good luck with your fork and safe riding.

 

Ok so I tried a ride yesterday at 0 psi ... Wayyyy better (and definitely better than with only one leg preloaded !). Maybe a bit too soft now for some soliciting trails, but still better than before ! I'm using a lot more travel of the fork, and it feels good !

Quick question though : Is it "normal" to ride like this ? Is it designed to be riden like this ? Or would it be better to take some of the oil off and add some extra air to get a oil+air kind of suspension ?

Regarding the adaptater, I probably did ordered the wrong one, but isn't the part going in to the fork the same on both models ? Because my problem was that the adaptater wouldn't fit on the fork's valve itself, not ont the pump.

I've seen in the user's manual that I needed some kind of tool to reach into one of the fork's leg and set the rebound. Do you know if my fork model actually have a rebound setting or if it's just that some other forks covered by the manual had one.

Besides this, a torque wrench, new oil and something to measure levels should be enough to take the fork apart ? I'm pretty sure the previous owner was not so much a maintenance fan, and I'm thinking as everyone keeps telling me that this is some good and reliable fork, I would be too bad not to take good care of it ( especially if it only needs an oil change .. )

Thanks a lot for your help, can't tell you enough how happy I was to ride such a smooth fork yesterday !

 

preload is always optional. In a perfect world springs would be matched exactly to your weight, but in real life that doesn't happen, so we use preload to attain correct sag. 0 preload is totally normal.

RE: the air adaptor, the end with the o-ring goes into the fork. If yours does not fit you either have the wrong one, or don't need it at all. Marz forks either take a shock pump+adaptor, or just a shock pump. At least, all mine were like that.

Do not play with oil levels to adjust preload. The oil weight and amount affects the damping, the spring (air or coil) is what supports your weight. Damping and spring rate must be adjusted independently.

I think the rebound tool was just a really long 12mm allen wrench. Look inside when you replace the oil and see if there's a socket in there.

Adjusting oil weight and volume is entering suspension nerd territory- I would leave this alone for now. Ride it as is for a while until you have a better idea what you like and don't like about the fork. Good luck!