Hi all
I have a 'used for racing' only NSR. Lately starting has been a problem, so changed the ignition switch. Sort of fixed it, but I do spray an 'Ether' mix down the carbs first.
Right!
So I went to put a rag over the carb inlets, and I got burnt! WTF?
Felt around, and found the 'rectifier' (?) was red hot. left side black finned thingo with numbers SH572-12
91
Has two sets of wires going into red plugs next to battery.
It's finned obviously to disperse heat, but 5 minutes running the motor, I couldn't hold my hand on it for more then a few seconds. Surely this is not normal? "Houston, do I have a problem?' If so, how do I fix it?
racer7

The rectifier needs to be mounted so that the metal undersdide is touching the rear subframe. Is yours mounted like this correctly? They do get pretty hot, and the earlier ones aren't finned, which is why they attach to the frame to help heat dissipate.
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NSR300R - Why did i ever have a 250...

Yep. the mounting is dirctly onto the sub-frame, 2 x 10mm bolts. I'd say it's at least as hot as a cup of tea made with boiling water, a minute for the T-bag to infuse flavour, and stick your finger in. Whoops..take it out!
When I say hot, I mean hot. You couldn't hold it for too long, else you'd get heat blisters I think. The brain says it's hot, let go!
Since the wiring harness backs onto it on the two 'bendable' straps, can't be healthy for the wiring....? If an original Road plastic seat was used, it would begin to melt it I'm sure. The RGV rectifier gets a littte warm, nothing like this though.....?

Are you running total loss?

Have you had a multimeter on the system? What's it running at? If it's tits up you may be on the way to frying your PGM, so I'd suggest you check the voltage before running it much longer...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

I've only had a multi meter on the battery to check that it's charging.
Where/ what else should I try to check?
racer7

My rectifiers get around 50-55 degrees C, that is so hot you can't hold them only touch a second or so.
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

And what were the results?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

I bought a new battery.
Then started the motor and checked battery whilst motor was running.
Was reading 14.14 volts.
And the regulator got hot hot hot.
I'm lead to believe that VFR400's are another Honda who's Regs get very hot, and are the weak point of that model?
My RGV (am I allowed to say that?) gets warm, and no problems holding it.
I've bought another Heavy duty Reg, but the mounting requires some thinking out!
A mate of mine explained the reg as an absorber of excessive voltage from the generator. And thus get hot. Err...OK if that's the way it is, so be it.
But I don't think it's right to get so hot!
More help needed please!
racer7

Was the 14 when the engine was revved or ticking over? If that's it at tickover, then you have a problem. It should only ever get that high with the motor spinning at 5000 or so.

It may be you've caught the regulator failing just in time!
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Results:
Fast idle 2000 RPM = 14.12 V
REGULATOR STILL GOT HOT HOT HOT.
I bought a Heavy Duty aftermarket item, and as luck would have it, the 3 pin and 4 pin connectors are wrong way round. Bit of cutting and soldering should sort it though. Tomorrows task! (Saturday)
I took the carbs off the MC21, and out them on the MC18. Started first kick!
Must be a float level problem? The 21 is a road bike, the 18 hasn't seen a road in 5 years, and has all the HRC goodies!
I'm travelling about 2600 Km to race this bike for 4 heats, long way if it doesn't go! 5 weeks to iron bike problems, or potential problems!
Your input is appreciated.
racer7

Results:
Fitted the 'Heavy Duty" Aftermarket Regulator.
Started Motor. No smoke or s[parks, so I must have solded wires correctly!
Running at 1500 - 2000 RPM, voltage at battery, 15.2V
The new Reg got hot, but not so you couldn't keep your hand on it.
Big change in Reg temperature!
1V more into new battery.
Am I going the right way? Gee, I hope so!
racer7

15.2V will cook your battery, it will run dry. 14.0-.3V is the norm
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

And after it's fried your battery, it'll likely fry your PGM unit too, and they're hundreds to replace.

Back to the drawing board I think...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Mmmm...so the flywheel spins around the wound coils, making current.
This goes to the regulator, which sends some to run the motor, and some to keep the battery charged, and somehow absorb the excess?
So would it be the generator coil needs rewinding?
My thoughts are that if it's buggered, wouldn't it make less 'electricity' rather then more?
racer7

The old one was probably working correctly, the voltage was correct, you only got nervous because of the heat.
On NSRs they get very hot. maybe you should go back to that one, and then, if you still think its too hot, mount it on a piece of alu with cooling fins or find a computer ventilator, 12V, and install it in front of the regulator.

If your connections from the generator to the rectifier/regulator and to the battery, are correct, i.e. they don't have any voltage drops, then your new regulator is not working correctly.

With that high voltage, it doesn't drop much of the original voltage from the generator, so of course it doesn't get as hot as the old.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom