Ducati Monster Motorcycle Forum banner

1 - 8 of 8 Posts

·
Premium Member
Joined
·
29 Posts
Discussion Starter #1
My current project: bringing my '97 m750 back to life with a' 98 m900 motor. After 60k and getting T-boned on my m750, the main bearing finally grenaded. I sourced an '98 m900 motor and am closing in on finishing it up.

My immediate question: there is a 3-lead bladed plug that comes off the engine on the stator side of the 900 where it is only a 2-lead plug on the 750. I've kept the 750's harness, if you haven't guessed - so I'm wondering if someone can tell me what's in the 3-lead plug... And if I can modify the 750 harness to accommodate it.

Additional questions, if anyone feels like answering:
  • Any obvious considerations come to mind? (Assume I haven't thought of them; I'm happy to read & see what I may have overlooked.)
  • Same coils should work as well on the 900 the 750, yes?
  • Mikuni 38s @ stage II w/ an open airbox + K/N should also work, yes?
  • How the heck are you supposed to remove the neutral switch?!
Thanks in advance; insight, oversight, second opinions always appreciated.

faster
 

·
Registered
Joined
·
269 Posts
How the heck are you supposed to remove the neutral switch?!
A couple of ways,
1. buy a special correct size, ring spanner that has an open section to slip over wire. Used by mechanics for working on brake systems as the open part slips over the brake tubing. very strong for this purpose.
2. Use a standard ring spanner and cut a section out using angle grinder. Not so strong and will flex open on tight nuts.
3. Remove the end plug or connector along the wire, a real pain.
4. Do what I do, just cut the wire, slip a normal ring spanner over and remove. When re fitting, join wire, best to solder and shrink wrap over join. simples.
 

·
Registered
Joined
·
47 Posts
I will have to follow this cause I also bought a low miles 98 m900 motor to put on my 97 m750 one day when mine needs replaced.👍
 

·
Premium Member
Joined
·
29 Posts
Discussion Starter #6
re: 3-phase regulators: it's not a clear plug-n-play swap. Replacement options for the 3-phase appear to have 2 molded plugs for the harness (a 4-blade plug, and a 3-blade plug), whereas the outgoing single phase unit has a single bullet connector (2 red wires), another pair of bullet connectors (yellow wires; back to the stator I presume), and a male+female pair (black & white wires).

Here's an example of the replacement rectifier

I see that the 3-blade molded connector comes from the motor/stator; that leaves the two connectors for the red wires, and the black & white pair in the M/F connector which I assume are now all grouped into the single 4-blade connector from the new rectifier: this is what I'll have to combine on the old harness. does anyone know if there's a particular arrangement to the wires? The product image for the new rectifier (link above) shows only two black and two red wires. I assume red goes to red, and it doesn't matter which; and the black wires on the new unit are the equivalent of the black & white wires on the old one.

My question, I guess: does anyone know if the two black wires in the new rectifier care which of the black or white wires from the harness they are connected to?
 

·
Registered
Joined
·
314 Posts
I suppose a wiring diagram for the 750 would be helpful. But that might be a time consuming hunt. I'm not positive, but all the wires from the old reg. may be hot. Some were only grounded through the case of the regulator. Since the system you're going to is much more straightforward, rather than trying to decipher the old one. I'd just focus on finding out where the harness wiring terminates. It should be mostly simple. A couple going to the battery through the main fuse, and 1 or 2 going to the fuse block. Those can all converge at 1 point with the 2 new red wires. Main thing is establishing if any of them are grounds. Which can easily be figured out with a voltmeter/continuity tester going to the motor and/or neg. battery terminal In any case, you may need to run a couple new wires to a solid ground from the new regulator. Preferably the battery post. The existing harness should cover it from there. I think Rick's sells the connector sets for a few bucks so You can alter the harness and don't have to do anything with the new regulator connector. may also end up with a leftover mystery wire that leads to the dash warning light. I suppose just capping it off is your best bet. Either way you'll lose the functionality of the battery light.
 

·
Registered
Joined
·
47 Posts
On ebay I purchased a China regulator for 900 with correct plug for 30 dollars. So when I decide to use my 900 motor it plugs right in. I only have 15,000 miles and runs like bat out of hell still.
 
1 - 8 of 8 Posts
Top