Bad Battery Or?

[torch]

With the engine running, measure the voltage between each pairing of the white wires on the harness side.

Actually, this is another good place to use a clamp-on ammeter -- this time with the connectors plugged in and looking for AC current, of course.

Attached is a nice article with pictures explaining the use of an oscilloscope to diagnose the charging system better than I did.

 

[RedRiderMN]

@K-Flyer

When I had a set of Motolites on my BMW, I replaced the incandescent bulbs with some LED bulbs. This significantly reduced the drain
on the electrical system.

https://motolight.com/product/super-bright-led-motolights/



Their website does NOT list the wattage for the LED bulbs, however.

 

[Rocnsanman]

Bike has over 65k miles. Problem just appeared a few weeks ago. I'm also surprised that battery discharges at 13.8. I'll try some of the other suggestions. But winter is coming and I think I will ride without the moto lights until I can get to checking it out. Wish I could find a mechanic in the area that I could trust. I have too many problems with back and knees to do much myself. Picture is of me at least 25 years ago. I've worn out somewhat since then.

Haven't we all ........

 

[K_Flyer]

Like a bad penny, I keep coming back!

To update this sad story, I talked to a guy at the local motorcycle repair shop who came to the same conclusion we all have, that it was the stator, perhaps along with a bum regulator. He had lots of good reviews, some from people I know, so I bought a new stator, regulator and related gaskets. The parts are here so I took my bike in this morning. He called me after an hour or so and said it was too big a job for him to tackle and I should come and get my bike and parts! Seems his experience is with Harleys, dirt bikes and quads. He said to go to a dealer, something I already tried. (See a few posts above). So now I have the parts and the additional challenge to find a Yamaha repair shop who is willing to just replace the stator and regulator without charging a lot to "diagnose the problem since we have already done that. Any suggestions for a good Yamaha repair shop near Sacramento?

 

[harper]

Ask SacramentoMike where he gets his work done. It may not be a Yamaha dealer.

Charles ended up replacing a stator in THIS THREAD.

 

[K_Flyer]

Finally fixed! Went to a recommended local shop who agreed it was likely the alternator but shop suggested buy rectifier/regulator as well. Parts came but the shop owner injured his shoulder and was not able to work on the bike. Found Capitol Yamaha on Maps as I was only familiar with PCP and Roseville Yamaha, both shops I'd had negative experience with. They had no problem installing the parts I had (OEM) and had a reasonable estimate. Turns out the alternator was fine and the R/R was the problem. When I took the bike in, the battery (key off) read 14.2 V and running at idle was 17+. So I'm back on the road and have a shop for work I need done. Mike, the head of the shop was good to work with. So now I have a new alternator to sell.

BTW, I was surprised how little work there was in the shop and, in the two visits there, saw no customers in the sales area. In general, even on good days, I see very few bikes on the road. Mike said there seemed to s=be a shift away from motorcycles in the last year or so..

As I noted in another thread, I donated to the server fund.

Edit: Note to self next time respond at the end of the thread!

 

[SkooterG]

Finally fixed! Went to a recommended local shop who agreed it was likely the alternator but shop suggested buy rectifier/regulator as well. Parts came but the shop owner injured his shoulder and was not able to work on the bike. Found Capitol Yamaha on Maps as I was only familiar with PCP and Roseville Yamaha, both shops I'd had negative experience with. They had no problem installing the parts I had (OEM) and had a reasonable estimate. Turns out the alternator was fine and the R/R was the problem. When I took the bike in, the battery (key off) read 14.2 V and running at idle was 17+. So I'm back on the road and have a shop for work I need done. Mike, the head of the shop was good to work with. So now I have a new alternator to sell.

BTW, I was surprised how little work there was in the shop and, in the two visits there, saw no customers in the sales area. In general, even on good days, I see very few bikes on the road. Mike said there seemed to s=be a shift away from motorcycles in the last year or so..

As I noted in another thread, I donated to the server fund.

Edit: Note to self next time respond at the end of the thread!

Glad you got it worked out! A R/R failure is very uncommon but anything can go bad. I would highly recommend you invest $30 in a Digital Voltmeter. A very quick and easy test with that would have shown that 17+ volts output while running and you would have known what the problem was. It would have prevented a lot of headache.