[mattcfish]

I'm a BMW R90/6 rider but I have an aftermarket Ducati 450W charging system from Euro Moto Electronics on my bike. I hear that the Voltage Regulator/Rectifier is the weak link to this system, so I thought I'd pick up a spare. I found a used one from a 1999 750ss (part#SH579B-11 printed on it). The price ($9.00) on eBay was so low that I had to get it. I've read that the 99 750ss had the upgraded 500w charging system. I've also read that you can use a 3 phase (3 yellow wires) RR on a 2 phase (2 yellow wires)
alternator just by leaving one of the 3 yellow wires disconnected. Is this true? The question is...can a Shindengen #SH579B-11 3 phase RR be used to replace a Ducati Energia # 343637 2 phase RR?

 

[danrduc]

Using 2 pair of diodes instead of 3 should be no problem, and you have a spare should one pair malfunction.
The 2 phase problem is more heat related from what I understand. On the Ducs with the problem, the regulator was not mounted in good airflow and would overheat. Remounting in the airstream is an important aspect of repairing a bad system. Another problem was with the oiling system for cooling/lubricating the rotor/stator. Something your system may not be dealing with.
You probably have different wiring already, another Duc problem[connectors].

 

[mattcfish]

Using 2 pair of diodes instead of 3 should be no problem, and you have a spare should one pair malfunction.
The 2 phase problem is more heat related from what I understand. On the Ducs with the problem, the regulator was not mounted in good airflow and would overheat. Remounting in the airstream is an important aspect of repairing a bad system. Another problem was with the oiling system for cooling/lubricating the rotor/stator. Something your system may not be dealing with.
You probably have different wiring already, another Duc problem[connectors].

Thats what I thought. I currently have the RR mounted in direct air flow. I'll keep the 3 phase unit as a spair for the road. I soldered all the connections.
No oiling system to worry about.

 

[Stick]

I know Ducati made a 350W alternator for "pre 1999" models of the belt-cam engines. Then the 1997 and 1998 ST2 had a 420W single-phase alternator (unique to the ST2). 1999 and up models of all ducatis got 520W 3-phase alts. So I don't know where you got a 450W one from. Also note that these coils are bathed in oil for heat management.

I use to own a R100RS, so I find your installation rather interesting. But, I'm assuming you're covering the rotor/stator with the BMW front cover? I don't believe there's any significant air that gets in there for cooling, so if it were me, I would treat your mod. with respect, and not load it all the way to 400+ watts, unless you monitor the temp of the windings...

EDIT: I visited the website where you got the alternator kit for your BMW. If they claim 450W, then I guess you could take any warranty claim up with them, if the system overheats due to loading.

 

[mattcfish]

This is the unit I'm using http://www.euromotoelectrics.com/category_s/58.htm
I modified it to fit a crank mounted ignition on the end. To do this I extended the front cover forward for clearance and added side venting. There's lots of air flow going through there.

Vehicle Manufacturer: BMW, Moto Guzzi
Application: BMW 70-76, Guzzi 74-93 ALL w/105mm stator; see above for 107mm stator
Make/Model: BMW, Moto Guzzi: Model 247, Airhead. All Moto Guzzi with tapered crankshaft
Model Years: 1970 to 1993
Vehicle Mfg. Part #: Not Available from Dealer
Power Rating: 450 Watts @ 14 Volts = 32 Amps




It's been working fine for years and lots of miles.

 

[mattcfish]

I know Ducati made a 350W alternator for "pre 1999" models of the belt-cam engines. Then the 1997 and 1998 ST2 had a 420W single-phase alternator (unique to the ST2). 1999 and up models of all ducatis got 520W 3-phase alts. So I don't know where you got a 450W one from. Also note that these coils are bathed in oil for heat management.

I use to own a R100RS, so I find your installation rather interesting. But, I'm assuming you're covering the rotor/stator with the BMW front cover? I don't believe there's any significant air that gets in there for cooling, so if it were me, I would treat your mod. with respect, and not load it all the way to 400+ watts, unless you monitor the temp of the windings...

EDIT: I visited the website where you got the alternator kit for your BMW. If they claim 450W, then I guess you could take any warranty claim up with them, if the system overheats due to loading.

Maybe a Duc is in my future. Thanks