Rectifier/Regulator gone bad?

My bike has been having starter issues:



I put in a new battery and the issues went away for about a day, but then came back with a vengeance.

I tested the voltage of the bike before this video and it was reading 11.3. Low. While cranking, it dropped all the way down to 1.2 volts, during one of the *clunks* when the starter motor stopped (see video).

I got the bike to start using a jumper battery but while running, the battery read 12.3 volts. Shouldn't it be up in the 14s?

So I then tested the Rectifier/Regulator. I tested it with this method:

I got readings of 395 on all three yellow wires.

I then tested the resistance in the wires. I got absolutely no readings on any of the wires. I reversed bias and got nothing. I tested the positive wire with the negative tong, and the negative wire with the positive tong and got a reading somewhere in the 400s, but as soon as I reversed (+ on +, - on -), I got no reading.

Sounds like no spark, does it kick start?

• checked the Points
• are the Coils within range of (4 ohms resistance typically)
• check spark plugs / boots may be worn put, most carry a constant residence
• check spark wires at both ends (open and clean contacts)
• is there connectivity to the Points
• check/clean all wire connections for corrosion
• check/clean Main Ground to frame
• use the kick starter instead of the starter

You've diagnosed your problem. You have a charging system issue. It's low, and draining the battery to compensate. It sounds like your Rectifier is working correct for continuity. Next step is check you stator output. Does the Voltage rise with RPM's? Starter, spark and all other electrical systems depend upon a proper voltage output from the charging system to work.

i was having an issue like this. what happen was wheb i put the sprocket cover on i pinched the wires from the stator to the reg/ rec so the reg/ rec wasnt getting the voltage it was grounding into my case check all wires and plugs.

I checked the continuity on the stator and read .9 ohms between the yellow leads, and .9 ohms between positive and negative (reversed bias). The manual says there should be 4.8-7.2 ohms between the leads?

MDZ1rider wrote: You've diagnosed your problem. You have a charging system issue. It's low, and draining the battery to compensate. It sounds like your Rectifier is working correct for continuity. Next step is check you stator output. Does the Voltage rise with RPM's? Starter, spark and all other electrical systems depend upon a proper voltage output from the charging system to work.

Regarding the question, the Voltage is supposed to rise (and fall) with RPM's...correct?

I haven't been able to get it to start since last week. But the last time I did have it running I checked and yes, the voltage would rise and fall with RPM's.

freakinbike wrote: I haven't been able to get it to start since last week. But the last time I did have it running I checked and yes, the voltage would rise and fall with RPM's.

We've got to get past this stuff, and be able to ride without fear of breakdowns...
I've had a continual charging issue, and pulled the (Electrex RO3) rotor out last week. Am ready to replace it with a beautiful OEM rotor bought used about a month ago. Just waiting on the correct thickness damper to arrive. Then I'll know if the Electrex rotor was culprit. The stator checked out good.
Plugging the bike into the charger every couple days (after riding down the voltage) was getting old.
Fresh-off the charger the bike would run great, but as the voltage dropped-off, the backfires came-on and headlight would dim.

That's exactly how it's been. I think I'm going to redo my rotor/stator as well.

Assembled and test rode today. The voltage (and engine power) is way better. The system is working much-better, and the engine actually gets hot now. Will see how well it holds up and starts the next couple days.
I believe the magnets on the OEM Kaw. rotor are stronger than what comes on the Electrex RO3 from the U.K. They certainly are a heftier thickness.
I intend to return the Electrex RO3-02 unit, since it never did put-out as it should have, and is still within one year since it was purchased. I'll keep the forum posted on my progress with that.

Had your previous rotor lost magnetism?

Ordered a new magneto and stator. I'm going to test both separately and see what's up. Stay tuned.