Charging system question
 

Ive been a honda mechanic since I was 18, and now Im 39 , so Ive got some years turning wrenches and tuning.
But I found your site and figured some people who are superhawk riders might have an answer that I cant find from a service manual or any local honda dealers mechanics for that matter. Hopefully your at least a mechanic on one of these beasts.

I had the charging system go out, and found the Regulator rectifier (the stock one thats epoxy filled) had overheated and needed replacement. The epoxy had distorted on the surface so i knew that the part was toast.
On replacement, the new one was the updated model with the superceded part number. This one had a heat-sink body with no visible epoxy like the stock one. Definitely an upgraded looking model, but same mounting.
(It's mounted on the right side of the seat frame right next to the turn signal relay.)
I was smart enough not to just hop on and ride without checking a few things first.
1st I measured the voltage at the battery before and after starting.
pre-start - 12.8v
post start - 13.6 v
So , I knew it was charging again.
(one note- the 13.6 volts drops slightly to 13.2 when revving the motor - possibly from ignition power consumption)
Knowing more could have led to the demise of the previous part, I held my hand on the heat sink to see how hot it got while Idling. Within a minute It got very warm, while voltage output stayed above 13.5 at the battery.
It kept getting hotter nad hotter over the next minute or two, until I shut it off.
It was hotter than i figured it should get, not enough to burn me hand but uncomfortably warm.
So to keep from damaging my new regulator I didnt run the bike more than 3 minutes.
Next I thought the Stator might have a short or something and measured the 3 leads(yellow) coming from it.
All 3 wires read exactly 0.5 ohms between each other, and no continuity to ground from either lead. Exactly what the honda book said was nominal. (0.2 - 0.5 ohms)

So theres no short in the Stator, and theres nothing more to the charging system other than a stator and a regulator / rectifier ... If any thing was wrong with the stator the ohm readings would be off, especially any kind of short.

So I get to my main question ....How hot do these rectifiers get in normal operation?
I mean Ive never felt how warm they get, on any bike for that matter ... for basic reasons.
Are they getting really warm while operating?
I dont want to ride the thing just to find out if I burn up a 160 dollar part, that would be silly to me.
Although the stock one without the heat-sink fins was basically a block of plastic that probably didnt conduct heat very well, and wouldnt feel very hot anyway,,, and this newer version since its got a metal body would naturally feel hotter on the outside. But seriously, I didnt think they would be very hot.
Electronically the other variable would be a possible short in the battery causing aggressive charging rate and making the thing get hot like that, but if the battery has internal short, it wouldnt hold a charge like it does.
Battery has sat for 4 days now since bench-charging and holds steady at 12.8 volts.

Any clues?
If you have a superhawk or RC-51 could you feel how hot the thing gets after a couple minutes of operation?
Im tempted to just ride the thing and see if I see or smell burning plastic or electronics, but at the same time I dont want to, lol.
Thanks for reading this...

Russ,

The R/R is designed to "burn off" all the extra energy the generator is creating but not using. It will actually get hotter with low electrical load on the system than if you had a high load.

It sounds to me like it's working as designed. Yes, they get hot! :)

It get's plenty hot... normal operating temp is way above "burn your hand" hot... It's function is to burn of excess voltage as heat... The old one did it by the metal plate on the bottom transfering to the subframe... The new one has the heatsink aswell...

yes, they get darn hot ! a lesson i learned here also.

tim

Most of us have done the r/r replacement. I used an aftermarket unit that was way bigger and more finned. There are threads on here about the east adaptation of an R1/R6 unit which is also way beefier and better heat sinked. By the way, its probably not safe to pilot a bike with one hand down on the subframe, I'd say thats a little more of your dime than you need.

Thanks .. well, I guess I will repack the two-brothers silencers with fresh fiberglass, and just take her for a spin tomorrow ! :cool:

I was curious why so many people at a local shop were swapping out their regulators, and selling them used , lol .

I freeking love this bike, and honestly havent ridden a better turning bike that doesnt shake at high speed without steering stabilizer.
Glad I found this site .

To keep them cooler use more electricity! It's counter intuitive at first, till you realize the stator will put out it's full power no matter what, then whatever you don't use the RR has to dump, and it does so by creating heat.

Russ,

I started a thread for you as per the email I sent you. I have moved the thread you started to the correct forum and merged the two threads.

Thanks man , I rode it all over Dallas today and nothing caught fire , lol.
What liberation ! after not being able to ride it for 2 months.
Glad I found a bunch of people who are as crazy about these bikes as I am.
After mine was recovered from the police, I repainted it a factory honda minivan color called "firepepper red"
I will post pics of my baby (beast) soon in the other forum thread when I take some.