so i went out to start the bike for the first time since last summer, and same old same , the starter Solenoid isnt clicking... so I check all my voltage , good to go there, take apart the start button and clean up the spring , and the contacts , all good there... So i take a screw driver and jump the connectors , Varoooom ... bike fires ..
I searched the forums and i dont see a List of Newer Upgrades for my bike ? I am currently running a Solenoid from a Kawasaki ZX10 .. and they work for about a year and then crash out and fail ..
what are the Solenoids in Newer Ducatis that work ...?

What should the Amp fuse size Be 20 or 30 ?

solenoids are a bit like spark plugs in that they will fit a variety of motors so the fact that its off a Kwaka doesn't really matter .... should last more than a year tho . Is it a high enough current rating for the 907 ?

Nah , ideally the solenoid should have minimal resistance to the flow of current to the starter , as should the cables themselves . What I was getting at is that if the solenoid of the Kwaka was rated at say 30 amps and the 907 starter draws 50 amps them it probly aint going to last long before frying the contacts. I don't know what sort of current the 907 starter draws but Im thinking a 900cc V twin would have to be nearly twice as hard to turn over as a 1000cc four banger and thusly maybe the ZX10 one just aint big enough current wise . Depends on how the solenoid fails . Is it the coil that burns out/ open circuits or is it the actual contacts that fail ?. In a low voltage circuit it takes bugger all resistance to have a detrimental effect ..... which is why the new bigger better quality cables show improvements over standard old ones ( even if they are still in good nick ) . 1/2 an ohm can make quite a difference

39740011A is used on:

Ducati 600 SS `95/97
Ducati 748 `99
Ducati 748 `99 SPS
Ducati 748 R `00
Ducati 748 SP, Biposto
Ducati 750 Sport
Ducati 750 SS `91
Ducati 750 SS `92
Ducati 750 SS `94
Ducati 750 SS i.e.
Ducati 851 `90 SP
Ducati 851 `91-`92
Ducati 888 Superbike `92
Ducati 888 `93->
Ducati 900 SS `90
Ducati 900 SS `92
Ducati 900 SS inj. `99
Ducati 900 SS/SL `94-`97
Ducati 906 Paso `88
Ducati 907 I.E. `92
Ducati 916 `94
Ducati 916 Monop.-Senna `95-
Ducati 916 `98
Ducati 996 Bip./Monop. `99
Ducati 996 SPS
Ducati MH 900 evo `01
Ducati Monster 600 `94
Ducati Monster 600 `98
Ducati Monster 600 `98 Dark
Ducati Monster 600 `00
Ducati Monster 750 `00
Ducati Monster 900 `93
Ducati Monster 900 `94
Ducati Monster 900 `98
Ducati Monster 900 i.e. `00
Ducati ST 2 `97
Ducati ST 4 `99
Ducati ST 4 S `01

And the later solenoid is 397.4.001.1A . It is exactly the same except it has the connector on a flying lead instead of plugging directly into a socket that it falls out of.