81 gs850gl 14.5 volts at idle. Drops when rpms go up.

[Guest]

I feel like I have been chasing the charging problem down for at least a year now.
Stator was bad when I bought it.
I purchased a Ricks Motorsport in August and was working great until last month. Went on a ride and just as I came to my driveway the battery was dead. I killed it trying to squeeze in between 2 cars. Wouldn't start because of dead battery.

I assumed through faulty testing the stator was bad again. So I sent it back and they tested 90 amp on all 3 legs.

The rectifier that came with the bike is a tiny one. Maybe 2in. x 3.5 in. and I had one sitting on shelf from a 550 gs.
So I decided to just swap it out. Even though the old tested fine with diode test. Red lead to black wire then across the 3 "yellow" then repeat with black lead to red wire. All were the same numbers across all.

And now to add insult to injury the bike runs terrible under 5000rpm.

Any help in diagnosis of or testing of other things greatly appreciated.

Also rectifier is connected to ground bolt on bottom of battery box with jumper from there to battery. Red wire straight to battery. Fuse link will be installed. Just haven't yet.

[509GsLover]

Should also note that all 3 stator wires go straight to rectifier. Eliminating the old headlight loop.

[tom203]

Do this test.. Disconnect stator leads from r/r. with your multimeter set on 200vac scale (or same scale that you would use for house outlet) While running bike to about 4k to 5k rpms, measure stator lead to stator lead and note the 3 readings. At same time and same meter scale, put one meter probe on any stator lead and other probe on good bike ground - you want to see a very low voltage reading, 0 would be best.

You probably haven't discovered the world of shunt versus series r/r's , but get ready.

[posplayr]

Also do the quick test as dropping voltage is associated with dirty connections as well. Fuse boxes are always suspect.

[509GsLover]

I pulled the wires to check.
I was getting .4 vAc on all 3.
I couldn't really get it up to 5000 rpm since cylinder 1 decided to stop firing.

[509GsLover]

Also the r/r that came on the bike has no indication of what type it is.
The one I put in is Ts

[hillsy]

You will need a fully charged battery to do the stator voltage test.

[509GsLover]

I will charge again and retest.
I need to figure out why #1 isn't firing before I can continue though.

[hillsy]

I will charge again and retest.
I need to figure out why #1 isn't firing before I can continue though.

If #4 is firing then it's either the plug, the plug lead or the cap. 1 and 4 fire off the same coil - 2 and 3 off the other coil.

Swap the leads over between 1 and 4 - if the misfire stays at 1 it's the plug, if it moves to 4 it's the lead or cap.

[tom203]

I pulled the wires to check.
I was getting .4 vAc on all 3.
I couldn't really get it up to 5000 rpm since cylinder 1 decided to stop firing.

.4 vac? use the same meter setting and check a house outlet.... You should see about 120 volts AC . Make sure you check one stator lead to good bike ground- this helps show that stator leads are isolated from ground.

[509GsLover]

You say swap the leads. I'm not sure what you are saying.
I did swap the plug from 1 to 4 and still no fire one #1. #4 fired fine still.

[posplayr]

FYI ac. Voltage output is proportional to rpm. Nominal is 80 vac@5krpm
you can scale it some but I would not test below 4k rpm . Higher voltage tends to find weakness in the insulation better than lower.

[509GsLover]

Okay. I tested my tester on house extension plug. Got 115 v.
I have my fully charged battery was at 13.1 turned key on volts dropped to 12.6. Key off climbed back up to 12.8.
Started it up and tried to test stator lead to ground and got .4 at first but also jumped around to 15.
I tested lead to lead and am getting 73 to 75 on all 3 legs.
Volts at idle 13.2.
Volts at 4000 rpm 13.2 when I let off throttle it jumps up to 13.6 and is now at 13.5 at idle.

[posplayr]

Okay. I tested my tester on house extension plug. Got 115 v.
I have my fully charged battery was at 13.1 turned key on volts dropped to 12.6. Key off climbed back up to 12.8.
Started it up and tried to test stator lead to ground and got .4 at first but also jumped around to 15.
I tested lead to lead and am getting 73 to 75 on all 3 legs.
Volts at idle 13.2.
Volts at 4000 rpm 13.2 when I let off throttle it jumps up to 13.6 and is now at 13.5 at idle.

Taking into consideration the lack of precision in what measurements you took, it look like you should change the stator.

[tom203]

Your measuring is iffy. But since you installed this new Rick's stator twice, you might have pinched the stator leads right where they exit the stator and are held in place by that metal bracket. This happened to a guy local to me - he reinstalled the stator carefully and got lucky. Magnet wire is easily bruised