VFR poor charging after new regulator install.

So like many 5th gen owners one day my battery stopped charging. It was the second time in 2 years, last time stator to R/R connector burned out. And now i think that R/R just gave up.

First i tested Stator, nothing shorted, resistance was the same across all phases, AC voltage vent from 30-60 volts. I also had an oscilloscope (picture attached) and all phases seemed to be alright.

So i replace my R/R with R1 (https://www.ebay.co.uk/itm/264333950743). Had to do some rewiring, as the original R/R had 8 wires (3 phases, 2 positive, 2 negative, 1 control) and R1 only had 5 wires (3 phases and 1 positive and 1 negative).

So heres the first thing i am not totally sure about. Can you connect both positive wires together? Multimeter showed that they were shorted, same with negative ones. I disconnected the control wire alltogether.

Anyways i started the bike on empty RR, just 3 phases connected and it had 15-16 volts which is fine. Problem is that as soon as i connected my motorcycle, voltage dropped to 12-13 volts, depending on the RPM. Battery is charging, but i think its too slow, as it used to be 13-15 volts with old R/R.

Any suggestions? Maybe i picked a R/R thats too weak?

 

That R/R from an R1 should be fine for the load... the three terminal side connects to the three yellow stator wires, the other is a power (Battery positive) and a ground. If there is resistance across the power/ground side of sizeable nature, it may be fried from being hooked up to reverse polarity... instant death. DAMHIK.

https://www.roadstercycle.com/Easy Mosfet Install.htm

 

Pretty sure i didnt reverse polarity, but i can check it again on zero load R/R if it outputs 15 volts. I could also try to connect postive wire directly to the fuse and battery positive bypassing the two stock wires.

 

If you trace the stock wires, according to the wiring diagram, the two reds and two greens out of the original harness are spliced into one red and one green not far after the connector... i.e., already joined. Further spliced from two 12V feeds, one from the 30 amp main fuse and one from the 30 amp starter relay fuse... check both, however, to eliminate any BS, wire direct to battery (with a fuse or 30 amp circuit breaker). Then take the green to negative battery... that is, as Roadster Cycle instruction does.

 

dere's onli one fuse, nod 2.

 

Okay so i connected RR positive wire through a fuse to positive lead, and negative wire straight to negative lead of the battery. On first start up the bike wouldnt start. The starter span the motor, but there was no fire. Turns out fuel pump wasnt working. So i hooked up the other positive wire to my RR positive lead and bike started.

Without any load RR outputs a nice 14.85 Volts on idle.


Thing is, once i load it up, it drops to 13 Volts, and this is without headlights. If i turn on the headlights, it drops even further to 12.4 volts. Ofcourse if i give it some revs, it jumps up to 13 volts.


Still a far cry from 14+ volts. Any suggestions?

 

check red plug on solenoid for d-m-ge.

 

So i measured stator output and it showed 30-60 volts depending on the RPM.

So then i connected it to R/R and measured voltage between phases there. It came out to 5-7 volts.

Well i guess my stator is dead, gonna remove it to check for visual damage and then probably order a new one.

 

Did you happen to check resistance between all combinations of the yellow wires, and that none of them are shorted to ground? That would another indicator whether the stator is fried or not. Seems odd you'd get 14.5 volts out of it if it were done.

 

So i took out the stator, right away i could see 50 shades of brown right up to dark black.


So yeah, even though voltage was fine under no load, wires werent shorting anywhere, and resistance between wires was okay, i still believe stator is close to dead. It just doesnt have enough juice to keep up the voltage required given load.

So the next thing is to either order a new stator, or get it rewound, as labor rates are quite low here. Ill try to do it until the weekend.

 

Mine at 65k miles..... it's obviously been hot, no real black.... R/R connectors fried..... new regulator, all good. I have a voltmeter going at all times, mofset FH020AA, 14.3 volts. Have you tried yours with a new reg first?

 

I mean its possible that the new R1 R/R is either faulty or too weak. I honestly dont know how to test it properly though.

 

What is the number on the end of the R1 regulator.... should be a mofset may be the older FH012 or the newer FH020. I don't know of a Yamaha with a mofset that failed, but of course anything is possible. I don't know how to test one either without some special equipment.

 

I ordered one from the link (https://www.ebay.co.uk/itm/264333950743).

And theres no part number on the end of it. Maybe its a fake one?

 

By that pic, definitely fake. Find a good used one on ebay for Yamaha FJ-09, late model FJR... they are Shindengen FH020's.

 

So i found 2 types in my country:
One is FH020AA 3.0 291F

https://dalys.lt/motodalys/yamaha/fjr-fjr-1300-a-rp23-108-kw/krovimo-rele/2414467

Another one is FH020AA 3.0 281F

https://dalys.lt/motodalys/yamaha/fjr-fjr-1300-a-rp23-108-kw/krovimo-rele/4875701

Anybody know whats the difference between them?

 

Nothing except the date code. Either will be fine.
You can also search other late model Yamaha in your region as model numbers may be different, e.g., MT-09, MT-07, etc.

 

So an update. Got a delivery of a FH020AA regulator. Gotta say fake one looks really similar to OEM one:






Got myself a new gasket for 4 euros aswell. Just need to assembly everything, and i got a free weekend aswell.

 

So probably last update, and with good news. So i reinstalled the same stator with new gasket, put up new copper wires from all the phases and installed new R/R. Seems like new RR did the trick - voltage is now a comfortable 13.5-14.5 volts depending on the load and RPM. Idle high beams 13.5, 5k rpm - 14-14.5 no matter what i turn on.

So thanks everybody for help, especially raYzerman, and keep off cheap fake ebay RR's.