Shindengen SH775 (2018)

gforce said:

I bought a new RM21 stator and rotor (both 'genuine lucas') when I had trouble with my PODtronics failing.
At the same time, I went for the Tri-Spark MOSFET instead of buying another POD.

I ran with the primary cover off for a bit so I could keep an eye on the spacing of the stator and rotor (belt drive makes it easy to do that)
That's when I found that I could feel the alternator getting really hot, too hot to touch the green plastic after just a short run.

I tried unplugging the stator and riding the bike (so on battery only) and the alternator felt cool to the touch - just the metal frame was hot, which I assume was from engine heat.
I didn't change anything else between these tests.

...and that has made me uncomfortable ever since.
I have been looking for an original zener, and recently found one (two actually) so am going to put one back on the bike.

Click to expand...

There is a very good explanation of how the various regulators work on granttiller.com
He explains where the heat goes and why.
The shorting type creates more heat in the alternator than the original setup does.
The open type sh775 or 847 do appear to be the very best, especially if the load and output are way out of balance, as some are.

Didn't know whether to come back and update on this thread or not - jeeeez, it's certainly gone off track since last time I looked in on it.

...but a couple of you were interested.


I fitted a NOS zener diode a couple of weeks ago, and have been for a few decent rides - a long one yesterday.

I am a lot happier, my stator is warm, but I can touch it, I think the warmth is now purely down to engine heat through the primary case mounting studs.
It was too hot to touch before.

The AGM battery seems to be charging fine (before and after each ride, I put my multimeter across the terminals and got 13.2 or 13.3 volts)
As another check, I put the battery on my smart charger, and the light went green after it did it's 'condition check' - not sure what that actually means, but I could hear the relay inside the charger click off when the light went green, so I'm taking that as good.

I am now putting the primary cover back on.