Filling Marzocchi cartridges with oil/bleeding the air out

[BK_856er]

as a side note: did yours have a plastic sleeve / spacer over the cartridge rod that fitted inside the spring?  they're the 43mm forks I was playing with in my air gap thing and rick at motocd said there should be a spring inner sleeve in them, but the one I had didn't have it.

Nope - all the parts that came out are shown in the pic, except for the large c-clip retainers.  Still got 'em in a box.  '07 M695.

BK

[ducpainter]

that, for a start.

in his initial post he said they were 40mm marzocchi.  the above is simply not correct for those forks.  it's a specific question about a specific part with specific info given that you and bk ignored and told him completely the wrong thing.

I was wrong.

Go ahead...hate me.

[motodoc]

Brad:

THANK YOU!  THANK YOU!  THANK YOU!  I thought I was REALLY screwing up and/or missing something given the advice I got.  To others who offered advice, thank you for your efforts.  We just can't know about every make and model of components on machinery.  The forks I have are, as Brad pointed out, just cheap.  As I pointed out, I'm doing the work at a machine shop.  The guy works magic with engines.  As a side note, he asked me if my Monster was jerky at low speeds.  YES!  His response was something like it is because it is basically two separate engines trying to operate independently.  He said that Ducati lines up the timing marks on the cam "gears", but what really needs to be done is to degree-in the cams.  I'v seen him do this on other high-performance engines, usually singles.  Once I sort out the obvious things (e.g. forks) on my bike, I am going to degree-in the cams.

To the matter at hand.  Brad: interesting that you should suggest putting the cap on the outer fork tube and pushing down rapidly.  The Race Tech book makes that suggestion by using a hand to cover the fork tube.  I think I'll try a modification of lifting up the outer tube, filling the inner tube to the top with oil, then exerting pressure using a long clamp or tie down, then come back in an hour or so.  My one concern is if I increase pressure on the oil to force it into the cartridge, will the air be able to move out of the cartridge from (what I would presume) a compartment with lower pressure into a compartment with higher pressure.  Perhaps that's why short, rapid compressions are successful.

Either way, thank you for the suggestion!

By the way, when I bought the bike, I had some work done at a shop in N. California.  New tires, timing belts, adjust valves, new chain.  A lot of stuff worth $1600 (about half what I paid for the bike).  The seat lock is missing as well, so I went to order it from the shop.  The mechanic let me know the Ducati no longer supplies the seat lock for such an "old" bike.  Then he asked if he could do anything else for me, so I asked for tips on bleeding the air out of the cartridges on the Marzocchis.  NO RESPONSE!  I didn't know these guys from Adam.  I went there on a recommendation from my buddy who has a Monster, spent $1600 and he can't give me any suggestions.  I understand the idea of being in business is to make money, but I'm not driving three hours so they can bleed the air out my cartridges.  I'll try a local mechanic here in Chico or go to Sacramento which is "only" 90 miles away before I drive three hours to Marin county (and pay $200 for an hour of labor).  I was able to get a seat lock off eBay for only $30 in about 10 minutes (a new one was going to be $120).

I apologize for rambling.

Jack

[ducpainter]

With regards to being jerky at low speeds, degreeing cams will help smooth things out, but changing your gearing will do more to help eliminate the 'snatchiness' at low rpms IMO. Ducatis are geared pretty tall from the factory for emissions/noise purposes.

Some people install a smaller (14T) front sprocket. I prefer putting more teeth in the rear.

You might check gearingcommander.com for a spreadsheet on gearing changes and their effect on top speed.

[motodoc]

ducpainter:  Thanks!

Lastly, regarding the forks:  Is it possible that the cartridges ARE indeed filling, but the compression dampening is virtually non-existent?  When I do fill the fork tube(s), air does bubble out of the cartridges.  It is just when I start stroking the dampening rod, there is almost no resistance during the compression stroke until about an inch from the bottom of the stroke.  Then on rebound there is dampening.  There is a lot of dampening at the bottom, but if I push the dampening rod about halfway down, then pull up there is definitely resistance, just not a whole lot.  It is the downward part of the stroke that has very little, if any, dampening.

I've already started to look for forks on eBay.  I'd prefer something that will "bolt on", but in my experience, when we start mixing parts from various machines there are always modifications to make.

I'll put the seals in and live with the forks I have until I can swing another pair or REAL cartridge forks.

Thanks to all again!

Jack

[DarkMonster620]

ducpainter:  Thanks!

Lastly, regarding the forks:  Is it possible that the cartridges ARE indeed filling, but the compression dampening is virtually non-existent?  When I do fill the fork tube(s), air does bubble out of the cartridges.  It is just when I start stroking the dampening rod, there is almost no resistance during the compression stroke until about an inch from the bottom of the stroke.  Then on rebound there is dampening.  There is a lot of dampening at the bottom, but if I push the dampening rod about halfway down, then pull up there is definitely resistance, just not a whole lot.  It is the downward part of the stroke that has very little, if any, dampening.

I've already started to look for forks on eBay.  I'd prefer something that will "bolt on", but in my experience, when we start mixing parts from various machines there are always modifications to make.

I'll put the seals in and live with the forks I have until I can swing another pair or REAL cartridge forks.

Thanks to all again!

Jack

If you are in the US, either think about re-springing them or trying to get S4R/S2R1K ones AND having them set for you . . . you might also want to try a heavier oil, 10W if you need them to be more 'stiff' .  .  . being there, done it . . . got re-sprung ones with some RaceTech internals also heard good comments from a few friends that are using Hyperpro

[ducpainter]

ducpainter:  Thanks!

Lastly, regarding the forks:  Is it possible that the cartridges ARE indeed filling, but the compression dampening is virtually non-existent?  When I do fill the fork tube(s), air does bubble out of the cartridges.  It is just when I start stroking the dampening rod, there is almost no resistance during the compression stroke until about an inch from the bottom of the stroke.  Then on rebound there is dampening.  There is a lot of dampening at the bottom, but if I push the dampening rod about halfway down, then pull up there is definitely resistance, just not a whole lot.  It is the downward part of the stroke that has very little, if any, dampening.

I've already started to look for forks on eBay.  I'd prefer something that will "bolt on", but in my experience, when we start mixing parts from various machines there are always modifications to make.

I'll put the seals in and live with the forks I have until I can swing another pair or REAL cartridge forks.

Thanks to all again!

Jack

Do both legs behave the same?

I know some later bikes have compression damping in one leg and rebound in the other, but I didn't think any Monsters of that vintage were like that.

[motodoc]

Both legs respond the same way.  Just for "kicks" I disassembled the second fork leg to see if it was set up the same way.  Sure enough. hardly any dampening until about an inch from bottoming out.  Just for kicks AGAIN, I filled up the second leg with fresh oil.  Got the bubbling, and the dampening rod behaved in the same manner.

Thanks for the advice on heavier oil!  That will be my "cheap fix" until I can get some forks.  Thank you also on the suggestions on what type/model to look for.

School starts Tuesday.  Friday is a faculty meeting.  I think tomorrow I'll "screw around" and put my Monster back together.

Thanks again!

J

[the_Journeyman]

That sounds about right.  I have a '99 M750 with the Marzoochis.  Both legs identical.  I went to heavier oil in mine.  It helps, but they're still not Showas or Ohlins.  I shimmed for a little more preload & also dropped heavier springs in while I had them apart. 

JM