part swapping ?

[bobst2]

with the limited production of the 907 what other bikes are the closest for parts source. i see a few st2 coments mentioned also 888 & 851. mainly thinking hard parts/mechanical stuff

thanks in advance

[persempre907]

For sure, the closest Ducati is... the Paso 906.
The ST2 has only some similar part as the engine (but 944 and not 904).
The 851/888 series has the same age, so elecrtics could be a little as on the 907.
But, all in all, both are very different from the 907.
Ciao

[ducbertus]

Hi Bobst2,

a lot of parts are interchangable with 750 sport, 900 supersport, 851/888 and of course the Paso family.
switches on handlebars- every type of that era
ignition-most likely 851/888
headlight-Paso family or Yam FZ 700/750 '86 -'88?
radiator-906-851/888
frame + supports - Paso family or only the 906
wheels- everything from that era
brakes- same story, watch the diam. of the discs
frontfork-the M1R is used in a lot of types incl Moto Guzzi and Laverda. watch the brake connecting.
rearfork- only 907
body parts-Paso family depending what you need.
fuel tank- 907 only?
rear suspension-paso family, but there are differences between 16" and 17" wheel versions.
crankcases- 900SS, 906, 907, 851/888, maybe not the SP4 and SP5.
cylinders/heads-907/ST2 (the latter preferred)

for sure I've forgotten something, but this is the majority.

Bertus

[JoKing]

engine - 907/ST3

Just a joke...

[Derek]

...frontfork-the M1R is used in a lot of types incl Moto Guzzi and Laverda. watch the brake connecting...

...cylinders/heads-907/ST2 (the latter preferred)...

The M1R fork is also used on the 851 up until 1990, which I'm sure you know.
The ST2 heads may well fit the 907, and presumably the 906, but there is no tacho drive provision on the horizontal head.
I picked up a pair of ST2 heads of eBAy for song a couple of days ago, then realized this.

[ducbertus]

Bob, Derek,

750 and 906 Paso have M1R with 280 mm rotors
'90 and '91 907 have 300 mm rotors
'92 907 have 320 mm rotors which is the same as on 851's

ST2 heads; indeed there is no provision for a tachodrive. this has to be machined. the protrusion in the casting of the head is still present.
I've a complete ST2 engine waiting and two sets of empty ST2 heads.
First set is ment to be cut open for measuring wallthickness of several areas at the valve guides and look for possibilities of twin spark. the second set is for realizing all this. the third set on the ST2 engine is a backup as the second set has to be scrapped.
first I have to complete my machine shop.

Bertus

[Derek]

ST2 heads; indeed there is no provision for a tachodrive. this has to be machined. the protrusion in the casting of the head is still present.

You reckon this is do-able? I have access to a 900SS head to measure from and some friendly machine toolists. The heads I have are bare but have been ported. I could source a set of valves then shim them up with all the rockers etc from the 907.

[ducbertus]

yes Derek,

this is possible.
measure up the tachohole and the threaded hole of the tachoattachment.
you can also use the 900ss head to adjust the fixture to position the ST2 head correctly on the milling machine or lathe. access to a milling machine is in this case more convinient.
IMO some other forummembers have done this before. Finnpaso?

succes!

[Derek]

yes Derek,

this is possible.
measure up the tachohole and the threaded hole of the tachoattachment.
you can also use the 900ss head to adjust the fixture to position the ST2 head correctly on the milling machine or lathe. access to a milling machine is in this case more convinient.
IMO some other forummembers have done this before. Finnpaso?

succes!

Hmm. Food for thought. Now has anyone got a set of ST2 valves going spare?

[Tamburinifan]

I have ST2 heads w a hole f revs.
Works fine.

[Derek]

I'm having difficulty in getting the tacho hole machined. I took it to a friend who does some machine work but after a few days he gave me it back. He reckoned that using the 900SS head to set up the alignment, he couldn't be sure of maintaing that alignment when demounting the SS head an mounting the ST head. Can anyone give me help me how this should be done?
Alternatively, what electronic tacho can I fit inside the 907 dash?

[ducbertus]

Hi Derek,

swapping a electronic tacho into a 907 housing is done also by someone on the forum. you have to browse as I don't remember who it was.
to machine the tachohole I proceed as following:
find a universal dividing head which can swivel and rotate. Or make an alternative by yourself.
machine a baseplate with a boss which potrudes into the recess in the head, just a the cylinder does in the head.machine the same dimensions as the cylinder. This ensures the centre of the head when you swap from a 907/900SS to a ST2 head. make the base plate so big (Ø150 mm)to have room to bolt down the head on the base plate through the stud bores. make one stud so big it has a snug fit in the head. this avoids rotation of the head during the head swap. Bolt down the baseplate on the face plate of the dividing head.
Now mount your head to outrigger the tachobore. once you have found the right position you can swap the heads and start machining the ST2 head.
In the past I made a fixture to machine twin spark threaded holes in 900SS heads. It had a base plate, a lockable tilting plate with a large bore (Ø200)
in the bore came two rings. the upper ring could adapt the head through the stud bores. this ring rests on top of the tilting plate and has a boss that potrudes in the bore with a play of max. 0.03 mm. this allow the ring to rotate.
the second ring rests on the bottom side of the tilting plate with also a boss in the bore of the tilting plate. by bolting the rings together they clamp on the tilting plate. this secures the position of head.
I hope this helps you a bit.

Bertus

[duc907]

Bob, Derek,

750 and 906 Paso have M1R with 280 mm rotors
'90 and '91 907 have 300 mm rotors
'92 907 have 320 mm rotors which is the same as on 851's


Bertus

The forks on the 851 are shorter then the 907 and will not work.

[JoKing]

swapping a electronic tacho into a 907 housing is done also by someone on the forum. you have to browse as I don't remember who it was.

Me. But not finished yet. I need months fo every little step.
Much work, 17 months old son, wife pregnant with some 50 days left...

[Derek]

Hi Derek,

swapping a electronic tacho into a 907 housing is done also by someone on the forum. you have to browse as I don't remember who it was.
to machine the tachohole I proceed as following:
find a universal dividing head which can swivel and rotate. Or make an alternative by yourself.
machine a baseplate with a boss which potrudes into the recess in the head, just a the cylinder does in the head.machine the same dimensions as the cylinder. This ensures the centre of the head when you swap from a 907/900SS to a ST2 head. make the base plate so big (Ø150 mm)to have room to bolt down the head on the base plate through the stud bores. make one stud so big it has a snug fit in the head. this avoids rotation of the head during the head swap. Bolt down the baseplate on the face plate of the dividing head.
Now mount your head to outrigger the tachobore. once you have found the right position you can swap the heads and start machining the ST2 head.
In the past I made a fixture to machine twin spark threaded holes in 900SS heads. It had a base plate, a lockable tilting plate with a large bore (Ø200)
in the bore came two rings. the upper ring could adapt the head through the stud bores. this ring rests on top of the tilting plate and has a boss that potrudes in the bore with a play of max. 0.03 mm. this allow the ring to rotate.
the second ring rests on the bottom side of the tilting plate with also a boss in the bore of the tilting plate. by bolting the rings together they clamp on the tilting plate. this secures the position of head.
I hope this helps you a bit.

Bertus

Thanks Bertus. I think I understand that.
I'll take it to my engineer friend and see what he makes of it.