Another R/R or Stator question (long)

So the story begins about a week ago after doing my own tire change on my '94 750. Took the bike out for a ride to make sure the tires were mounted/balanced right. On the return I noticed that my speedo would occassionally drop to 0 then come back online. I got all the way back home and the the bike died at the bottom of my driveway. The battery was dead so I took it to the local auto shop to get it tested/charged. Turns out the battery is bad, so I replaced it. Once the new battery was charged up, I began testing the electrical system per the service manual. First I turned the bike back on and measured the voltage being returned to the battery, there was none, so I tested the R/R. The only test for the R/R I could find is measuring the resistance between terminals. Everything seemed ok. I moved on to test the resistance at the terminals coming from the stator. According to the service manual there should be no continuance between the posts and the ground. I was getting some resistance (which, correct me if I'm wrong but that should mean that there is continuance). I had to go out of town for a week so the bike sat for a while. I finally got back around to testing tonight. I tested the resistance at the stator terminals again and got 0.0 which is less than before, but still means that there is continuance. The battery is a little low (12.2V) from the testing, but I started the bike back up anyway to try and do some more tests. This time the stator was returning about 0.1V when the bike was turned on and the voltage leak test seems to return about a 1.5V loss through the system . I'm pretty sure that the stator is bad, but I dont want to have to replace both the R/R and the stator, so any input would be greatly appreciated. I'm going to have the new battery charged tomorrow and try to start from scratch again. I'll try to keep y'all posted.

 

Take the r/r to the dealer and have them test it: they have the correct ohmmeters to test it. VFRs are notorious for r/r failures.

 

Took it to the dealership this afternoon and they told me that they "think it might be fried.." (Way to encourage confidence). Got home and hooked everything back up just to see if disconnecting everything had let the gremlins out of the system (it hadnt) and after the bike warmed up I noticed that the R/R was starting to smell of burning electronics. Ordered a new one tonight, hopefully this will fix the problem.

 

Yea, don't feel bad, I had to take mine to the dealer twice. The first time they told me it was fine so I went to Sears and got a new battery. Then it did it again. Back to the dealer and the service rep didn't even know the r/r could be tested! I had to tell him how to do it, then they charged me $15 for the lesson. Well, they tried to anyways, they are still waiting for the $15 and this was back in July. I certainly wasn't about to pay them $230 for a new r/r so I got one from GDL Cycles in Florida for $120. Built the way Honda should've done it in the first place.

BTW, if you need to get a new battery, get it from Sears. They sell the exact same one as Honda; has the same Yuasa numbers and everything. Plus it's $20 cheaper. Take the old one when you go, they can match it exactly.

 

What is a R/R?

 

Rodney, R/R is short for regulator/rectifier. It's part of the charging system on motorcycles. On VFR's this has been a long time known issue for which there are many suggestion on fixes and many listings of symptoms.

 

Some of us on Ozvfr call it a @#&% ***/***!!!!

 

I must be one of the lucky few. My VFR is a reliable as a brick. In 6.5 years of ownership, the single only thing that's ever gone wrong was my throttle cable. The return cable worked fine but I could never get it to apply more than 1/2 throttle. I rode in this manner to the closest Honda dealer & they had it fixed in less than 25 minutes. Other than that, not a worry at all. My charging system produces 13.8 volts at 100f outside & the battery holds a steady 13 volts year round. They single biggest thing you can do to ensure your battery/charging system is up to snuff is ride year round. Pulling the bike out of the garage & running for 15 minutes once a month will not cut it. Make an effort to ride at least once a week at least 20-30 minutes each time year round & your bike will be much happier.

KC-10 FE out...
lane:

 

Unfortunately the only way to really know if you have a bad RR is to order a new one and see if anything changes.(I have done the diode test on a bad RR and new RR and got the same reading so that doesn't really work.) Did you test the output from all three of the stator terminals? They should all be the same or one of the windings could be fried. Also did you do a leak test to see if you have a short somewhere? Use Electrosport's troubleshooting flowchart. It works wonders, but I don't recommend buying their RR's. I put a new Honda RR on mine after a bad battery fried the original. The new RR's are much beefier with a heat sink plate. I also did the PC fan mod to mine because sitting in traffic in AZ when it's 110F is not good on your RR. Good luck!!!

 

Rev,

How has this R/R treated you? I need to purchase one and I'm having a hard time talking myself into paying $230 to the dealership for a new one.

 

I got one from bike bandit and it was about $200 plus shipping. I thought I had another bad one so I ordered another one but from ridenow.com and it was only $140 plus shipping. So, now I have an extra sitting around or to throw in the bag on a road trip just in case! Shop around. You can get the Electrosport ones for $100, but you have to do some wire mods because they aren't perfect connections.

 

Works great. I did have to rotate it slightly as the thing is about an inch thick (versus 1/2" for the stocker) so the mounting stud wasn't long enough. The wire harness plugged right in. It's built like a car amp and its not painted (which I prefer) plus if you wanted to mount a CPU fan to it it'd be alot easier. Got mine from GDL Cycles (http://www.gdlcycles.com/asp1/rezdetails.asp?ItemID=10-115) for $120 and it turned out to be a Rick's Motorsport Electric's unit. There are other places to get one; Ron Ayers has them for $168 and ServiceHonda for $160 (P/N 31600-MY7-305).

Having been an airplane mechanic for ten years, I can tell you the best way to fix a problem is not to replace components until it is solved, it's to test each component according to manufacturer's specifications. That means you take the r/r to the dealer and have them use the correct ohmmeters to do the test. As I've stated before, all other electrical tests can be done with a decent quality multimeter, testing the r/r shouldn't.

 

My '94 went through 2 regulator/rectifiers. 1st one was in the first week I had the bike. Dealer replaced free of charge. 2nd went about 40,000km later. That replacement was still good after another ~45,000km when the bike was written off.

The only complaint with my '00 is 1 flat battery earlier this year.

 

Well Mr. Stud airplane mechanic, I was just speaking from my experience with my charging system problem. I did all the tests too (all components) and it pointed to a bad RR. I replaced the RR and the new RR was doing the same thing, thus RR not needed. I certainly am not so stoopid to suggest that you keep buying and replacing things to find the problem. I have confidence in my own mechanic ability as well, from growing up around it! AND I have had the "all knowing" MC mechanics tell me the same is wrong with my bike that I figured out already even with their ohm test. hwell: