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 Post subject: Stripping Marzocchi rear shock
PostPosted: Thu Dec 11, 2008 7:49 am 
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Joined: Wed Oct 06, 2004 12:00 am
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Location: Nottingham, UK
model: 906 Paso
year: 1989
Has anyone stripped one of these rear shocks? I am contemplating it and if there is any guidance out there it will be appreciated.

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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Fri Dec 12, 2008 7:51 pm 
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paso grand pooh-bah
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Location: Finland
Sorry, I have played JUST with Paso Öhlins and later version of Marzhocci "Duo Remoto", but NOT with this earlier version of Marzhocci... To that later version its still possible to find spare part kit, but i am not sure, does that kit fits to this earlier Marzhocci unit.... :)

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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Dec 13, 2008 1:38 am 
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Joined: Sun Feb 19, 2006 12:00 am
Posts: 135
Location: Bolivar, Ohio USA
model: 750 Paso
year: 1988
I've disassembled mine to thoroughly clean it but never to the damper internals; I guess that's what you need to know right? If you just want to disassemble the spring, collar nuts, gas body, etc., you can remove the load on the spring by loosening the collar nuts. First use a caliper to measure the top nut's distance from the shock's top shoulder so when you reassemble everything you can put the top nut back to the exact measurement. Loosen the top nut then the bottom and the spring load will release. The spring is not compressed too much so all load will release before you run out of threads on the shock body. From there the other parts just slide off the shock.

A local shop who handles Marzocchi said he would work on it if I needed so I'm guessing parts and rebuild service is readily available. Hope this helps.

Tom


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Wed Dec 17, 2008 7:42 am 
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Joined: Wed Oct 06, 2004 12:00 am
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Location: Nottingham, UK
model: 906 Paso
year: 1989
Thanks guys, I did get to take it apart and have been informed by Marzocchi UK that Maxton Suspension can rebuild it.

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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Fri Jan 23, 2009 3:39 pm 
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Joined: Mon Aug 02, 2004 12:00 am
Posts: 34
Location: Santa Fe, USA
model: 750 Paso
year: 1988
I'm here in the US and want to rebuild my Marzocchi shock also. I finally found a Marzocchi manual that is very close to being this shock. At least it indicates approximately what I will find when I open the shock. From what I can tell, the rebuild kit would only have an assortment of o-rings and one oil seal. From what I hear on the forum, the rebuild kit for the Paso 750 does not exist. Is this true? If so, does any one here have a good source for o-rings and seals. I'm thinking of taking it apart and measuring these and hunting them down from an independent source. I even have a new OEM replacement shock to put on while I do this, but it too has a slight leak from the shaft oil seal. Guess 20 years on the shelf has hardened the seal. I've looked at the cost of replacement shocks. Only one I can find is at Works Performance, custom build up but with comp/rebound adjustment, but at $600US. I don't have a problem with the stock shock performance, so am looking at the rebuild. I know my way around tools and such, so it's not rocket science, just a matter of finding a source for the wearable parts. Thanks for your help.

Oh, yes, I've lurked here for some time. Have had my 1988 Paso for 10 years. Has a Weber that runs great (after 2 years of fine tuning, don't ask) and still love to ride this bike. It will always be in my garage.

George


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Fri Jan 23, 2009 4:27 pm 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5359
Location: southern Germany
model: 750 Paso
year: 1987
George,

do you have the manual as a file or could scan it ?
Even if it`s not 100% this shock it may help someone.

G.


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Fri Jan 23, 2009 5:44 pm 
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Joined: Mon Aug 02, 2004 12:00 am
Posts: 34
Location: Santa Fe, USA
model: 750 Paso
year: 1988
The manual is for Marzocchi Duoshock 45, 45 Remoto, and 38 Remoto. I have it in PDF format. It's the closest thing I've found to our shock with the remote res. Instructions are multi-language. Let me know where you want me to email it. It's 11.8MB in size so the detail is good.

George


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Fri Jan 23, 2009 11:24 pm 
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paso grand pooh-bah
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Joined: Tue Jul 29, 2008 9:50 pm
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Location: Hilltown,Pennsylvania
model: 906 Paso
year: 1990
http://www.mcmaster.com/
source for most things mechanical in the US, which of course does not help you much try ......http://www.simbles.com/
I have a spare if you run into trouble..............
Hey George,would like to compare notes on your weber experience if you can stand it :lol:

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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Jan 24, 2009 1:03 am 
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Joined: Mon Aug 02, 2004 12:00 am
Posts: 34
Location: Santa Fe, USA
model: 750 Paso
year: 1988
Weber? Sure. It's much bad mouthed but is really not bad at all. What do ya want to know.


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Jan 24, 2009 11:33 am 
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paso grand pooh-bah
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Joined: Tue Jul 29, 2008 9:50 pm
Posts: 3207
Location: Hilltown,Pennsylvania
model: 906 Paso
year: 1990
curious as to where you ended up with your jetting
I have been searching for a pair of 4.5 auxiliary venturi tubes for my 44dcnf without any luck so far
have changed my emulsion tubes to f47 which seem to have solved most of the low rpm flat spot around town. Also swapped out the stock coils for a pair of dynatek coils but with the weather and my work situation have not had the chance to give them a try as yet

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Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Jan 24, 2009 1:06 pm 
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paso grand pooh-bah
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Posts: 3061
Location: Finland
higgy, try to spend one day(surely weekend!!!) with internet and try to search, what cars have that Weber and search such carb from car wreckers.... There must be many of them, cause that Weber came such time, that just those cars are now in wrecking...

Also there MUST be many "Weber maintainers" in USA, so try to contact to them and ask about such veturi tube... :thumbup:

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Antti http://www.youtube.com/watch?v=HeKOh3XoXPg&NR=1
KTM 990 Adventure -08 metal dark grey
Paso 750 -89 red/metal grey
Paso 907IE -91 red/metal grey
Paso 907IE -91 red
ST4S -02 red/metal grey
ST2 -01 red/metal grey
Volvo V70 Bi-Fuel Classic/titanium grey


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Jan 24, 2009 7:30 pm 
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paso grand pooh-bah
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Joined: Tue Jul 29, 2008 9:50 pm
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Location: Hilltown,Pennsylvania
model: 906 Paso
year: 1990
Antti
I have tried all the suppliers here and in the UK as well as Italy. They all are surprised they dont have it but all say it is no longer available.
I have been offered a set of 4.0 which I might try in the end,from Pierce here in the US They are where I got the f47 emulsion tubes I got the info on the jetting from a Ferrari forum. In Ferrari/Maserati land it is quite a common swap to put 44dcnf in place of the original carbs and they all love them.
I am happy with the way the weber works now,but being the way I am I know it could be better so I will keep looking or just bite the bullet and make my own adapter for the tubes I have.

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Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sat Jan 24, 2009 7:33 pm 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5359
Location: southern Germany
model: 750 Paso
year: 1987
George`s manual was added to the downloads

G.


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 Post subject: Re: Stripping Marzocchi rear shock
PostPosted: Sun Jan 25, 2009 12:13 am 
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Joined: Mon Aug 02, 2004 12:00 am
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Location: Santa Fe, USA
model: 750 Paso
year: 1988
higgy wrote:
curious as to where you ended up with your jetting


Well, let's see if I can make this brief.
First, all the standard things that are talked about. It has stock air box with a K&N filter. Fuel pressure regulator in place set at about 3 psi. Of course, the original Paso had a brass fuel jet of some sort inside the fuel hose to restrict flow. So they were thinking about psi, but that jet is long gone now and thus the pressure regulator. No change in fuel accelerator pump. Tried both brass and plastic floats. Made no difference, set level at stock setting. Did change the float valve about 6 years ago, just to make sure it was not leaking.

I bought the bike in 1999 in Denver (5000 feet elevation). It was well taken care of and little did I know how well at the time. It ran ok but had the stumble, not bad but there. Then moved to sea level and got it running well, and I'm now in Santa Fe at 7000 feet elevation. Rejetted it last summer after the move here. Seems to be good now at this elevation.

I haven't gone to the extremes some have by changing venturi or drilling holes in the butterfly valve. Here's what I have discovered. The webers are more sensitive to lots of things than Mikunis or others. Air temp, humidity, elevation and all. Once I got it right, I discovered that come winter it was off a little. I played with every piece of brass in the carb and tried lots of combos using the color of the plug and the cleanness of running as my guide. I don't race but I've rejetted lots of Mikuni, Keihin and all over the years so I'm not new to it. The jets I ended up with are 60 Slow, F36 Emulsion, 160 Air Corrector, 145 Main for 7000 feet elevation. But I need to explain this, it's not as it seems.

There are three factors that have a lot to do with Weber running well. The Emulsion tube, the slow jet and the level of the fuel in the emulsion tube cavity. The fuel level is of course controlled by the float level. The slow jet has a much greater effect than you might think. I found I had to go a little rich there because its influence travels further up the RPM range than you might expect. But the key is the Emulsion tube. Though mine is an F36, some of the holes been soldered up and redrilled to affect when and where the fuel emulsion happens. I used to have a diagram of the drilling. Next time I have the Weber apart (not planned any time soon), I can remap it and make a new diagram of it if anyone is interested.

Here's what helped me alot. First, when the bike is cold it is lean (thus a choke is needed), as it warms up it gets richer. All bikes, as you know, do this. So for testing I used to watch how it ran cold and hot. Then I took it on a ride that went from sea level to 6000 feet in mountains. As you go up, the bike runs richer, less air. So between the hot/cold and elevation change I would get a good indication of if the bike was lean or rich. Did it run clean at some combination of those four things.

As I said, I don't race and there are those out there much more knowledgeable about these things. So your results may vary. But after trying lots of stuff I kept coming back to a modified emulsion tube and slightly rich slow jet. Stock pipes, no new coils, no special spark plugs. Just the basics. Is the venturi too small/big for the 750? Don't know. There is a limit to going too small or too large. I just don't believe that's an untunable issue on the stock bike.

So I've probably clouded the water on this issue rather than cleared up anything. But hope this helps some out there still trying to tune the Weber. My only complaint about the Weber is all the plastic body work I have to take off to do anything. But I do love the way the Paso looks, even after all this time.


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