servicing a marzocchi rear shock

discussions specific to the 907IE
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torpedo51
Posts: 17
Joined: Mon Jun 06, 2011 6:31 am
model: 907 I.E.
year: 1991
Location: Los Angeles,CA & Reno,NV

servicing a marzocchi rear shock

Post by torpedo51 »

When I fully compress the rear shock, the rebound appears to be undampened for the first 80% of the return travel, then is dampened for the last 20% of travel.

Is it low on oil/N2? Service or replace it?
Making a mechanic out of me: 1988 Paso 750 | 1991 907ie
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paso750
paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: servicing a marzocchi rear shock

Post by paso750 »

Servicing is for sure cheaper. There`re used ones for sale once in a while but one never knows their real condition.
If you decide to service yours take a close look at the damper rod. If the chrome is chipped or damaged that maybe the reason why an oil seal leaked. Over the time you`ll also notice that the swingarm linkage is oily.
I had that on my first shock so I took it to the main Marzocchi importer. They told me I`d need to replace it as it was impossible to find a spare damper rod. According to them polishing or rechroming was no durable solution.
So it would be important to find out why the shock doesn`t work properly anymore, if due to a damage or just as a matter of age.

G.
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torpedo51
Posts: 17
Joined: Mon Jun 06, 2011 6:31 am
model: 907 I.E.
year: 1991
Location: Los Angeles,CA & Reno,NV

Re: servicing a marzocchi rear shock

Post by torpedo51 »

Ok, I do understand the need for an undamaged shaft.

What affect does the N2 charge perform? Could this cure my rebound problem?

Is it possible to perform a "leakdown" test on the unit to verify the seals/o-rings are bad?

Can I add oil myself somewhere?

Do we have a manual for the specific unit used on our bikes?

I'm asking because whenever I go to a shop around here without some idea of what to expect, they flat out screw me.
Making a mechanic out of me: 1988 Paso 750 | 1991 907ie
angelix
Posts: 338
Joined: Thu Nov 29, 2007 2:38 am
model: 907 I.E.
year: 1990
Location: UK

Re: servicing a marzocchi rear shock

Post by angelix »

torpedo51 wrote:Ok, I do understand the need for an undamaged shaft.

What affect does the N2 charge perform? Could this cure my rebound problem?

Is it possible to perform a "leakdown" test on the unit to verify the seals/o-rings are bad?

Can I add oil myself somewhere?

Do we have a manual for the specific unit used on our bikes?

I'm asking because whenever I go to a shop around here without some idea of what to expect, they flat out screw me.
when a shock is "bad" there is no way of fixing it unless it is completely overhauled.
On ebay you can get the original Kit (30$?) and it is not a difficult job, however if you take it to a shop they will charge you at least 150$ plus parts (in Italy over 200...).

I just did mine and went through the "shop route" as i discovered that mi shock was in bad state as well as the other TWO I got from ebay....

Funny thing I ended using a PASO750 shock which was adapted by a specialist to the 907 (this will need very specific tools as the old unit has a nitrogen tank that can filled only with specific tools) and I have to say I was VERY VERY surprised of how well it works.

Ah yes, 2 weeks after doing all the mods, I found on Ebay a Marzocchi Duoshock unit, brand new, for less than 50$ :wacko: :banghead: :banghead:
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: servicing a marzocchi rear shock

Post by paso750 »

Here`s the manual we have on the site
http://www.box.com/s/yaishmk894lgxoazkxzj
Adding oil is not possible unless you open the shock.
Ah yes, 2 weeks after doing all the mods, I found on Ebay a Marzocchi Duoshock unit, brand new, for less than 50$ :wacko: :banghead: :banghead:

Isn`t that always so ? :mrgreen:

G.
User avatar
torpedo51
Posts: 17
Joined: Mon Jun 06, 2011 6:31 am
model: 907 I.E.
year: 1991
Location: Los Angeles,CA & Reno,NV

Re: servicing a marzocchi rear shock

Post by torpedo51 »

Help!

The shop that is rebuilding the shock can't find replacement seals or seal head.

Does anyone know where to source these parts or have a cross referenced part from another vendor? Its a 14mm ID with a 40mm OD. My seal head has the hex head to accept a wrench rather than two holes for a pin driver.

Thanks!
Making a mechanic out of me: 1988 Paso 750 | 1991 907ie
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: servicing a marzocchi rear shock

Post by paso750 »

these two shops list the complete rebuild kit. They do list every part number so one needs to ask about availability.
http://www.store.commoto.com/ducatistor ... 76960.html
http://store.proitalia.com/ducati-oem-s ... 18422.html

Have you checked at a Ducati dealer with the part number (36640011A) ?

G.
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