Suspect Rectifier/Regulator

Eivind

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Apr 22, 2018
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Norway
My previous bike, Honda CBF1000, had a design flaw that caused the stator to burn out regularly. After 3 years and 3 replacements I decided to trade in the bike. I just didn't trust it enough to go any kind of distance with it. Is this a Gen 1?
 
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jbrown

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Sep 25, 2012
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Novato, CA
While it's possible there was some defect in that stator contributing to the failure, it seems more likely that there was an excessive load that was responsible. Your R/R could still be bad, or you may have some wiring short that put a high load on the stator. The R/R shunts current to ground to regulate the output voltage. If it is faulty and shunts too much current, it could overheat the stator.
 

oKLRider

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Ada, OK
While it's possible there was some defect in that stator contributing to the failure, it seems more likely that there was an excessive load that was responsible. Your R/R could still be bad, or you may have some wiring short that put a high load on the stator. The R/R shunts current to ground to regulate the output voltage. If it is faulty and shunts too much current, it could overheat the stator.
I'm a little worried about that, too. Once the new stator gets here, and installed, I'll rerun checks on the RR to make sure it specs out. Hopefully so.
 

ruenjou1

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Oct 23, 2017
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CA
Most motorcycles use a permanent magnet generator with a shunt regulator. While it's simple, the problem is the regulator shunts excess current to ground and causes the stator coil to work at 100% all the time.

Super Tenere has few stator failures while other makes/models suffer frequent stator or regulator failures. I replaced mine with a series regulator and at the same time replaces head lights with LED lamps. This reduces stator and regulator loads greatly.
 

oKLRider

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Ada, OK
...and at the same time replaces head lights with LED lamps. This reduces stator and regulator loads greatly.
I've been running LED replacement bulbs for awhile. I've also been running 3 pod style LED aux lights for the last 30k-40k miles. I think they're around 28w each...
 

oKLRider

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Ada, OK
So if you've been following along, it's back together...functionally. The electrics still aren't buttoned up as I'm still checking some things. The new stator is putting out consistent AC voltage readings from all three legs now, and I'm getting 13-14v at the battery now at RPM. :cool:

I ran another check on the R/R to be sure, and I'm still getting ~15.5v straight out of it at RPM. That's ~1.5v higher than the spec of 14v. Is that difference enough to overwork the stator? Is it out of spec enough to need replacing? Is it what caused my original problem? I'm thinking yes, but I really don't want to drop $150 on a new regulator. :confused:
 

oKLRider

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Ada, OK
Where are you checking it at when you say you're getting 15.5V straight out of it?
By disconnecting the supply (black) connector, the one that feeds the starter relay/battery/system, and checking voltage directly from the regulator pins with the engine running.
 

OldRider

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I don't think I would do it that way. Check right at the battery with everything hooked up and that will tell you how many volts is getting to the battery. To check the stator output you unplug the stator and check between the three white wires. A to B, A to C and B to C. This is AC voltage and with the engine revved I would expect to get 60-70 volts AC. The RR takes this AC current and turns it into DC to charge the battery.
 
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