Problem with Marzocchi 2005 66 RC
- Thread starter aceto3
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- marzocchi 2005 66 rc
most likely, your oil level is too low, or you had the bike upside-down for a while.
If it was that simple it would get normal again after bouncing on it for half a minute...
Your fork need some love man, give it a proper service.
Not neccesarily. When you go to cycle your fork you got slow your rebound down and really compress the fork. If you don't you can be doing it for 30 sec. Also if it's been upside down for a while it will take a bit longer.
That is likely, but it's also an old fork, if it has enough oil the reason is a blown damper, which does happen after years of service. I'm going to go with "low oil" for now though.
definitely got the right oil weight in there?
Did you cycle the cartride to get all the air out before you put the top cap on. After you add oil in the cartridge side you should cycle the cartridge until you don't hear the sucking sound. My guess you got air in there and with the top caps on you can't get rid of the air.
There in fact is the problem....... Even Marzocchi says dont service the fork like that. generally when you measure it out like that you overfill the fork and blow the damper when your trying to use it.
Zokey will tell you flat out... specially on older zokes to measure it with oil height not by measuring the amount and adding.
IE, my 07 66 I set it at 67-70 mm from full at full compression....... Give them a call, super friendly people, will give you a perfect oil height to go with
really? theyve said the opposite to me when they rebuilt my fork both times.
did you purge all the oil out of the damper as well as out of the leg? or just drain the leg? do you get full travel if you pull the spring? does the compression know do anything?
also, if you over-turn the adjuster knob you can get the port stuck open/closed and then after the port no longer adjusts, the knob just spins and spins (much more common on a fox than marz).
also, if you over-turn the adjuster knob you can get the port stuck open/closed and then after the port no longer adjusts, the knob just spins and spins (much more common on a fox than marz).
Yes really, have always done zoke forks by oil height vs volume measurements..... PSecially with older ones you cannot open the cartidges on, you end up never being able to get all the oil out of the cart to begin with, and end up overfilling it.
I think it all depends how you change your oil. If you just pop the tap caps off and pour the oil out, the oil height is the best way. If you do a complete break down and cycle the cartridge, measured amount is good. I also run a little less oil than recommended also, maybe that's why I don't blow a cartridge. Also we are pretty much accomplishing the same thing, just differ ways.
Well, yes, I'm assuming the damn thing works before hand. I guess I've been changing my oil wrong, but it's been oh, about 5-6 years since my 66 "shipped", so I kind of forgot what height it had back then. The thing is, if the fork worked correctly before, this method does not require looking at height or online volume, it's pretty fool-proof for an open-bath fork. If you know what you should know for servicing, you can easily diagnose low/high oil level anyhow...
I look up the oil "volume" when I completely drain the fork and get rid of the oil before I can measure it, but I also know that those settings are usually too low and more is necessary...I kind of know what % to go "over" due to experience over time...
I look up the oil "volume" when I completely drain the fork and get rid of the oil before I can measure it, but I also know that those settings are usually too low and more is necessary...I kind of know what % to go "over" due to experience over time...
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Thats just it..... it is phycisally impossible to do a complete tear down on this particular fork... You cannot take teh carts apart to get all the oil out, not without destroying them......... I have done these forks for many years with excellent results and NEVER have I been able to cycle enough oil out to use a volume measurement without the fork being overfilled.
This is the technique I learned from barnetts.......... In fact there is a tool made for it.. basically its a syringe with a clip on the end of a tube. The tube has measurements on it to tell you how deep into the fork it is, so you fill it up, cycle it, then suck out the excess.....
Sorry shouldnt have said complete. Knew somebody would've caught it. When I take the cartridge I cycle it for a little while. I know there will be some residue left over in the cartridge. Measure it out is just easier for me. It works for me. Also I put less oil than recommended, 300 I believe for the 888, and I put about 290. Even thinking a little less next time. On another point, nice sig, like it.
It's not as complicated as some people are making it out to be. For the damper to not work at all something must actually be broken / wrong internally. You don't NEED to cycle the damper to get air out, that will all happen when the fork is in use (hello, gravity). Overfilling won't blow the damper either, the only thing it could possibly blow is the seals.
aceto3 -
I think you did the right thing by putting the 220ml in each leg.
If the fork has no damping then it is possible the damper cartridge has some problem with it, perhaps something is broken inside. Unfortunately they are sealed cartridges so if something is broken it may be difficult to fix.
If you remove the rebound side damper (the one that does most of the work), you can remove the spring and put it in a tall container of oil and cycle it by hand to see if it is working. I don't have a 66 but on the 888 of the same year you had to be very careful where the topcap threads onto the shaft - there was a red nut that could break the shaft if overtightened. Just FYI, not sure if the 66 is the same.
aceto3 -
I think you did the right thing by putting the 220ml in each leg.
If the fork has no damping then it is possible the damper cartridge has some problem with it, perhaps something is broken inside. Unfortunately they are sealed cartridges so if something is broken it may be difficult to fix.
If you remove the rebound side damper (the one that does most of the work), you can remove the spring and put it in a tall container of oil and cycle it by hand to see if it is working. I don't have a 66 but on the 888 of the same year you had to be very careful where the topcap threads onto the shaft - there was a red nut that could break the shaft if overtightened. Just FYI, not sure if the 66 is the same.
Yes air and oil will mix in the fork, but if you put it together with more air in the cartridge than oil, I don't think you can get all the air out of the cartridge. Air should be on top on oil on the bottom, meaning oil in cartridge and air out of the cartridge and on top. Like a upside down bottle of air in the tub. You won't get the air out till you tilt the bottle. If you don't cycle the cartridge to fill it with oil then it's going to filled with air. Then you put the top caps on there is going to be no space on top for the air. The air then stays in the cartridge. This is will explain why you have no rebound dampening when you turn the bike from being upside down. You have to cycle the fork to force oil into the cartridge and air out. This my reasoning, sorry if it sounds confusing. Also no disrespect to the OP I don't know if he can tell he has no compression, no rebound would be easier to tell.
I think you're really reading into this too much, and I actually don't think you're correct either. An open bath cartridge is designed to draw oil into itself.
Those old marzocchi forks are dead simple, and there is a lot of space all around the very thin cartridge, and there are holes at the top and bottom of the cartridge - so the circulation of both air and oil happens very readily. If you were to just fill the fork up with oil and not cycle the cartridges first, I'm pretty sure everything would still work absolutely fine.
It's good practice to cycle the cartridges free of air, and I'd be surprised if the OP didn't do that - but the only consequence of not doing that might be a little extra air pressure trapped in the fork - not an empty damping cartridge that is providing no damping whatsoever.
I suspect the problem is something other than that personally, especially if he's put 220ml of oil into each leg and is getting zero damping.
Those old marzocchi forks are dead simple, and there is a lot of space all around the very thin cartridge, and there are holes at the top and bottom of the cartridge - so the circulation of both air and oil happens very readily. If you were to just fill the fork up with oil and not cycle the cartridges first, I'm pretty sure everything would still work absolutely fine.
It's good practice to cycle the cartridges free of air, and I'd be surprised if the OP didn't do that - but the only consequence of not doing that might be a little extra air pressure trapped in the fork - not an empty damping cartridge that is providing no damping whatsoever.
I suspect the problem is something other than that personally, especially if he's put 220ml of oil into each leg and is getting zero damping.
Well that sounds fairly normal, seeing that the marz specs for years were too much oil. the 888 however is not so critical to a little overfill like the 66 is.... 10ml over and you lose full travel on the 66. One of the more sensitive open bath forks I have worked on.
For the record, a 66 takes about three pushes, if that to "purge" the cart, very VERY simple carts in these forks... In fact after letting your bike sit upside down for a night its usually good to go before you hit the trail on the drive over without cycling. They are not bad about trapping air at all.
Good points. Yeah I got kink of stupid on last post. I will think about these things, especially the three push, the next time I tear mine apart.
Yeah the 66 is a retardely simple fork to work on pre 08 design..........
They were also particular to the quality of oil as well as weight......
A side note on older zokes such as this one in question...... I have seen alot of times were someone is telling me the adjustments dont work at all...... and the reasoning is that the adjustments just such to begin with, really not much modulation on the in between on these, and depending on teh comp damening it may never be something you can feel in a parking lot test, but will need to go out and make a run to nitce any changes
I am still banking on oil levels being off though, seen a few that have also been too low and it just slamms on the top out.....
They were also particular to the quality of oil as well as weight......
A side note on older zokes such as this one in question...... I have seen alot of times were someone is telling me the adjustments dont work at all...... and the reasoning is that the adjustments just such to begin with, really not much modulation on the in between on these, and depending on teh comp damening it may never be something you can feel in a parking lot test, but will need to go out and make a run to nitce any changes
I am still banking on oil levels being off though, seen a few that have also been too low and it just slamms on the top out.....
Yes I agree, the 66 and 888 is easy to service. That's one of the main reasons I like marzzochi so much. I think I'm one of the few that got a good 08 66 and 888 model with no bushing slop. I feel boxxers and 40's require to much maintenance. The 2012 fox 40 peaked my interest with them inverting the internals.
Sooooo any word from the Op as to what was going on?
Inquiring minds of RM want to know
Inquiring minds of RM want to know
Yes, I'm wondering what he found out also.
Thanks for the answers. I don't think it is from the oil because I always put 220ml in each leg and there was no problem. I am thinking of other reason of the problem could it be somethin disconected so when I turn the buttons nothing happened. When I changed the oil this time I pay attention to the little holes which control how fast the oil is gething through them and they actualy doing the work of the rebound of the one side and the compresion of the other and I saw that the holes are not closing like before when I turn the buttons they stays open and in my opinion this cost the problem. Could it be somethin separated and to get no conection betwean the buttons and the lowest part. And why bouth sides stoped working and if this could be the problem how to get everythin in place?
Thanks again for your answers.
Thanks again for your answers.