900SS fried regulator...stator check??

[Laddie907]

Guys...
my 907ie is just fine...but I've smoked a regulator on my 1997 900SS
from what I can determine the alternator's a single phase (two yellow wire) unit - same (or similar) to the 907ie
what I need is the test figures for the altenator to make sure it's not an internal fault..I don't wanna fry a new regulator..

funny - normally it's the yellow wires that over-heat and melt but in this case the regulator just about caught fire - heaps of thick smoke from burning plastic inside the unit...the wiring is all fine.

the only manuals I have for this bike are for the 1991 model (which is useless) and the 2001 model - but that has a 3 yellow wire alternator.

any help or references would be appreciated.

[higgy]

Stator check . Check the stator for opens
and grounds using an ohmmeter as shown in figure 7-5.
If the reading is low when connected from any stator
lead to the frame, the windings are grounded. If the
meter reading is high when successively connected
between each pair of stator leads, the windings are
open. A short circuit in the stator windings is difficult to
locate without laboratory test equipment due to the low
resistance of the windings. However, if all electrical
checks are normal and the alternator fails to supply rated
output, shorted stator windings are indicated. Check the
regulator in the next step before replacing the stator

This is in general what you would do to check any stator/regulator setup

[Laddie907]

thanks Higgy...

what I need are the ohms (no, not the Buddhist monk "ommmmm") and AC Voltage figures for say 1200RPM & 4000 RPM
usually these will have a tolerance, too...

I want to check the stator at running temp to see if it's intermittant short
the bike was cruising at 100km/hr when it smoked up last time - engine just getting to operating temp...
the reg would have had a good flow of air; it was only about 35 degrees celcius - so not too hot for overheating.
I want to eliminate a thermal problem...

[higgy]

I would pay attention to all the wiring and especially the regulator grounds. Stator problems are really pretty rare and usually are due to insulation brake down or just plan bad grounds and terminals along the way to the regulator.
Sorry can't help on the specs,perhaps someone else can or try a one of the many ss sites around.

[jcslocum]

I have a 900SS manual laying about. I'll try to find it and post the proper pages.

Found some pages from the Haynes manual. I hope this helps.

[Finnpaso]

If You follow Jon's pages(Haynes manual for Supersport), You can figure out whatkind stator should be. Same also with rectifier.

For testing insulation You will meed "Megger", or samekind insulation tester, as normally multimeter gives only 9 vots to test brobes, what is totally too low voltage for testing insulations.

Basically all stator wires have to be well insulated from stator ground and stator gives AC voltage output, higher rpm about 70 Volts is quite normal.

[93IE]

I had stator and regulator problems a while back. It was necessary to rewind the stator and replace the regulator. With everything working well now, it produced 90 vac at 1500 rpm and 116 vac at 3000 rpm. Regulator output is 14.0 vdc. Mine had melted the yellow wires and smoked the regulator. I replaced the regulator and repaired the wires, but had low ac voltage from the alternator, about 60vac max.

Good luck

[du907]

Take a look at this site. I bought a stator and rotor from these guys a couple of years back. No problems, everything was OEM and fit and works perfectly.

http://www.electrosport.com/street/stators.php

du907

[93IE]

I tried to buy one from them about 6 months ago, and they were no longer available from them. I had to rewind my own at a friends motor shop.
Preston

[Finnpaso]

New stator coast about doubble compared to new regulator, so problems have to be solved from bike what have lost stator, or regulator....

Most of these problems (in 907IE) are caused by dirty connectors between stator and regulator..... too dirty connectors=>too much resistance=>too much heat=>smelted connectors, maybe shortcut to ground and You can imagine that result is lost stator and lost regulator.... and if very unlucky, also battery....

[Laddie907]

thanks guys...the whole thing has gone well.

I didn't megger the stator; nearly did but took the risk...so far OK.
there was an additional 30 amp fuse near the battery that had blown - and probably saved the stator

the unit I bought was a lot cheaper than through Ducati and is a genuine Ducati part - go figure!!
http://www.euromotoelectrics.com/category_s/62.htm
I appreciate your help

[Finnpaso]

That is "MAIN 30A FUSE" in 907IE and its between rectifier + pole (output) and battery + pole (and fuse box main fuse). Very cheap from local auto spare part shop and not so bad idea to have few for spare. It tries to protect bikes other electrical equipments from faulty regulator(too high voltage/current/power from rectifier to battery). Its not between stator and regulator, so it dont protect stator. Sometimes rectifier failes so, that it gives to much/too less output to battery side and sometimes so that it put its input poles to shortcut to ground and that is dangerous to stator, as then stator wires are in shortcut and stator blows....

U were lucky this time, as stator was ok.

Not so bad idea to check ALL fuses after something blows!!!! i really mean ALL...