Ducati Monster Forum

Moto Board => Tech => Topic started by: polygamus on December 10, 2011, 10:20:53 PM

Title: Monster Engine Number then further Tech info
Post by: polygamus on December 10, 2011, 10:20:53 PM
Gday All,

I'm looking to get some engine parts from a Monster to fettle an older engine I'm building.  While not everything is interchangeable, lots of it is.  The monster engines are plentiful (relatively massive productions numbers) and from all reports, generally robust (good metallurgy and production methods).

First things first though.  Can anyone give me a year model for this engine number?  Probably Australian delivered.

ZDM748A2C*01407??

The 'C' might be a C or a G or even a 6, the ? means just that.. I don't know what number/letter it is.

I have an image but it's not the clearest..  but it's safe to say it's an older carbed model (alloy belt covers - wet clutch).

I'm after the year model initially so it will be easier to work out what internals it has.  Then we can get down to the serious business.  Any takers?

Cheers,

Garry
Sydney Oz.
Title: Re: Monster Engine Number then further Tech info
Post by: Raux on December 11, 2011, 02:42:55 AM
ZDM= Ducati
748= 750
A= Aircooled
2= 2valves
C= carburated

that's all I got so far
Title: Re: Monster Engine Number then further Tech info
Post by: Raux on December 11, 2011, 02:50:14 AM
Do you have the VIN of the bike it came off?

a pic would also help as there are a few changes over the years that might be recognizable.
Title: Re: Monster Engine Number then further Tech info
Post by: polygamus on December 11, 2011, 03:30:23 AM
It's a bare engine so the VIN is not available, only the engine number.. and as is always the way, only 'most' of it is decipherable.  Images on the 'net seem to indicate it's pre-1998 but that's as far as I can go so far.

I rarely get this right (posting images to forums) but here goes..

Alternator side:

(http://i554.photobucket.com/albums/jj413/polygamus_pantah/M750altside.jpg)

Clutch side:

(http://i554.photobucket.com/albums/jj413/polygamus_pantah/M750clutchside.jpg)

Looks like it's worked OK.

On the whole, what I'm trying to establish is where (what year/models) straight cut primary gears started being used.. my old beast, an 84 model 650SL, uses helical cut primaries.  I'm building up a new 'warm', dry clutch motor and I wanted to get my hands on some straight cut gears and a couple of other bits 'n bobs.

(edit:  I should have stated it's 2 valve, air-cooled, of course.. sorry.  It's the only engine config I play with so it's familiarity that breeds my presumptuous stupidity)

Appreciate any insights.

Garry.
Title: Re: Monster Engine Number then further Tech info
Post by: Raux on December 11, 2011, 08:34:52 AM
Dry Clutch?
There were no small case dry clutches were there?

I think we've had this debate before.
Where's Duck-Stew when you need him?

He's done a conversion and knows those motors inside out

edit: just did a quick search and saw a 1990 750 Paso with a dry clutch...hmmm

and here's an 88 for sale

http://www.ebay.com/itm/1988-Ducati-750-Paso-Engine-Motor-/390267336365?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item5addbef6ad (http://www.ebay.com/itm/1988-Ducati-750-Paso-Engine-Motor-/390267336365?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item5addbef6ad)
Title: Re: Monster Engine Number then further Tech info
Post by: polygamus on December 11, 2011, 06:00:33 PM
The problem with early Pantah's, that is the 500/600/650 units from the early 80's, is that the clutch wouldn't hold up to much more power than came standard.  The 650 suffered clutch slip, even in standard trim, if you used the loud handle in anger.  The solution is a dry clutch.

Dry clutches existed on factory racing machines from around 1983, check the F2 machines of that era. 

The 86 and onward 750F1 (and Bimota DB1) had a dry clutch.  The Paso range as well but these later machines had a different shaft spline arrangement making them generally unsuitable.

What is mainly needed isn't so much the clutch as the gearbox shafts, as the input shaft was XXmm longer to accommodate the clutch hub etc.

Since F1's and DB1's rarely get busted up for spares, dry clutches can be had from later Cagiva creations that used the Pantah motor.

Getting back on topic, the early Pantah's also used power sapping helical cut primary gears and spun the gearbox too slowly (1:2.22 ratio).  I'm hoping I can get my hands on some straight cut gears with a slightly better ratio.  It's my understanding that straight cut gears are used on most later machines and the ratio is closer to what I'm after.

Garry
Title: Re: Monster Engine Number then further Tech info
Post by: Howie on December 11, 2011, 07:43:25 PM
You should to speak with Duck-Stew, he's been there, done that.
Title: Re: Monster Engine Number then further Tech info
Post by: ducpainter on December 12, 2011, 04:37:57 AM
Most later motors do use straight cut gears.

They have 2 ratios...2:1 and 1.84:1
Title: Re: Monster Engine Number then further Tech info
Post by: brad black on December 12, 2011, 06:18:24 AM
it's a 97 motor i'd say.

750 motors were dry clutch up until 750SS engine number 1500 or something like that, some time in 91.  then they went wet. 

primary drives - 750SS â€" up to engine number 007223 â€" 36/71, 1.97:1
      engine number 007224 onward 31/62, 2:1

600 and 400 had the 2.28

all straight cut afaicr.  don't recall seeing helical pd gears for a long time.
Title: Re: Monster Engine Number then further Tech info
Post by: Raux on December 12, 2011, 06:28:42 AM
Quote from: brad black on December 12, 2011, 06:18:24 AM
it's a 97 motor i'd say.

750 motors were dry clutch up until 750SS engine number 1500 or something like that, some time in 91.  then they went wet. 

primary drives - 750SS â€" up to engine number 007223 â€" 36/71, 1.97:1
      engine number 007224 onward 31/62, 2:1

600 and 400 had the 2.28

all straight cut afaicr.  don't recall seeing helical pd gears for a long time.

not to steal this thread,
would a dry clutch from this era fit on a 696 then?
Title: Re: Monster Engine Number then further Tech info
Post by: brad black on December 12, 2011, 03:14:52 PM
all these motors had the slave in the cover, not the lh side of the motor with the pushrod across.  you couldprobably make it fit if you wanted too, people do far more insane stuff here.