Looking to upgrade to a 3 phase charging sytem

[levi_red]

Just joined the DMF today.  Ciao to all of you,

I have a 94 M900 that comes stock with a single phase charging system.  I am wondering if anyone knows how much trouble I will have to go through to upgrade to a 3 phase charging system.  I am already assuming "a lot", but I am a proficient mechanic, machinist and fabricator.  So before I tear the old stuff out and buy the new stuff, I figured I would ask if anyone has gone down this path before.  I've already done a search on this forum's history to see, and I didn't find anything.  If I missed it, please inform me.

Thanks for your help

[Raux]

buy a new motor

[Duck-Stew]

buy a new motor

Although Raux's response seems a bit curt, it's accurate.  The charging systems do not interchange w/o swapping crankshafts and at that point...  it really is better to buy a later model 900 motor for your scoot.

There are upgraded regulators if you want and you could buy a European left handlebar switch which would allow you control over the headlight.  That nets a few amps which can help with starting of the bike...

Welcome to the board and good luck keeping your older M9 up & running!

[levi_red]

Thanks Duck-Stew,  your post is actually helpful.

If the crankshafts are the limiting factor, I assume by that you mean the way they interface with the stator/magnent.  So I imagine the bolt pattern doesn't align, or the shaft diameter is too big, or it is splined instead of keyed, or something of that nature.  To me that all sounds fixable as long as there is enough space for the necessary components.  Maybe non ducati components?  From your description of your own bike, I think you will know what I mean.  If the end goal is to keep the existing motor and generate 3 phase power, there must be something that will at least fit or could be made to fit.  Has anyone on this forum actually tried this?  or know someone who has?

[Raux]

I think I read of a person with an ST2 doing it.

I have one and it's died on me once.

[Duck-Stew]

I haven't ever tried this, but from what I remember the 2 crankshafts are splined VERY differently.  You'll need a 3~ alternator cover (not hard to find) to complete the swap as the 3~ alternators are larger in diameter.

After you find the 3~ cover, you'll need to drill & tap it for the 2x M10x1.0 oil return feeds from the oil-filled barrels of your '94 M900.

If it were me:  I'd find a 3~ crankshaft, alternator and side cover and just rebuild the entire engine if you're so inclined to swap all the bits.  You wouldn't be machining on the 1~ crankshaft with it in the motor anyways...  

[Raux]

hence my 'buy a new motor'

[Duck-Stew]

hence my 'buy a new motor'

Sometimes more of a 'map' response is required versus a 'destination' response. 

[ducpainter]

Crankshaft length is an issue also. The early bikes had a shorter shaft and a different side cover from the next gen single phase systems.

What about the single phase system is driving this mod?

[Howie]

Crankshaft length is an issue also. The early bikes had a shorter shaft and a different side cover from the next gen single phase systems.

What about the single phase system is driving this mod?

Good question.  Single phase was an issue with FI, not so much with carbs.

[Speeddog]

I'll have some pics later.

[koko64]

Good question.  Single phase was an issue with FI, not so much with carbs.

Hey LR, are there starting or charging issues, plans for heated accessories or extra lighting? Are you planning an FI conversion?

With beefed up wiring and good connections, my 1995 M900 starts and charges well.

[ducatiz]

I would just pick up a later motor and retro fit the carbs and exhaust.  Much easier than what you propose.  It is possible to do but unless youve got gobs of time and money to blow it will be far easier to put the later lump in. 

The later 900ie engines have better cams too.

[levi_red]

This is what I was looking for.  Great feedback. 

The original cause for this inquiry was a blown stator, and questionable regulator and battery.  I prefer to put things back better than I find them and in this case that seemed to include an upgrade to a 3 phase charging system.  How that happens has been the discussion above.  I'm encouraged by the information I have gained and am sure this will contribute to an impending winter project.  Thanks guys.  

[Ahks]

I love winter projects

Have fun with yours.