Electrical problem I think...

[dvd_macneil]

I'm having a problem with starting my 1980 GS750 when it is hot. I just went out and checked the battery and it showed 12.45V. Started the bike up and left the tester hooked up to the battery at idle it showed 13.9V. When I brought the RPM to about 3000 and upto 5000 and the reading went to 13.45V. Is all this normal? Yesterday I went out for a ride and shut the bike down after about 45 mins. When I went to start it it acted as if the battery was nearly dead. Took a boost from a car and it fired up. Rode home 15 mins and shut it down. Same thing, nearly dead. Checked voltage it was 12.5V What is going on? Any help is appreciated.

[Nessism]

The factory manual for my 550 states the voltage should be between 14 - 15.5 volts at 5,000 rpm. You might want to go back and double check yours but it sounds like your regulator/rectifer is faulty.

[Killer2600]

Battery might be dead.

[Steve]

I just went out and checked the battery and it showed 12.45V. Started the bike up and left the tester hooked up to the battery at idle it showed 13.9V. When I brought the RPM to about 3000 and upto 5000 and the reading went to 13.45V. Is all this normal?

Yes, this is quite normal. When I start our 850, the voltmeter shows about 14.1. When the engine is running faster (and while going down the road), it will show 13.8 or so. The charging system can only put out so much, and it takes more to run the engine at higher speeds, so a small drop is normal.

Hopefully, when you "took a boost from a car", the car's engine was OFF? :shock:
If you connect a running car to your bike, your rectifier/regulator will do its best to try to regulate the car's output,
usually rather unsucessfully.

If you MUST use a car to jump your bike, make sure the car's engine is OFF.


.

[dvd_macneil]

Don't think the battery is dead. It shows 12.5V even when the bike won't start. Yes the car was off when I got a boost. Could this be a starter problem? Would a battery get hot and do this sort of thing?

[nabrams]

Filthy starter insides are a very common cause of the problem you describe. See the many posts on this topic.

[mixongw]

http://www.stockers.com

[tconroy]

Check your ground connection on the r/r.Cut it off and go directly to the battery for a better ground.Also cut the solid red wire and go directly to the positive side of the battery with that.Make sure you dont have any hot or melting wires from your stator to the r/r.If you are using that plastic connector get rid of it and put the push connectors on from your stator to the r/r wires.This will enxure a positive hook up between all your electrical wires.

[03svrider]

hey tconroy. you seem to know what you're talking about. i'm replacing the r/r on my 81 gs450l with a new electrosport to HOPEFULLY keep the main fuse from blowing as intermittently as it does. should i go with the wiring sequence you suggested above?

[tconroy]

DO THE STATOR PAPERS FIRST TO DETERMINE WHAT IS WRONG AND THEN As long as your battery is good and you have cleaned all connections.Check all your wiring.A bad r/r or stator should not blow a fuse.Check all you hot wires and make sure there is no bad spot or slice that is grounding out on the frame somewhere.Go to the stator papers in the garage section of the front page and see what up there.Follow it just like it says and you will know if the r/r or stator is bad.I would be concerend about why the fuse is blowing.Is it the right fuse for that connector? 15amp? Is any wiring showing hot or melted look.Wire will get hard and brittle if they are overheating.I know how to fix the charging systm but I think the fuse thing is something different.I have just replace my stator and r/r but never had a blown fuse.About wiring the stator and r/r like I said,Yes that is the way to do it.r/r ground to battery and the SOLID RED wire to the + side and the other three to the stator.There will be one wire that will come out of the harness that hooks up to the r/r.If you still have the plastic connector just cut off the connector and wire exactly like it was, matching the color of the wires up without the connector.

[bakalorz]

DO THE STATOR PAPERS FIRST TO DETERMINE WHAT IS WRONG AND THEN As long as your battery is good and you have cleaned all connections.Check all your wiring.A bad r/r or stator should not blow a fuse.Check all you hot wires and make sure there is no bad spot or slice that is grounding out on the frame somewhere.Go to the stator papers in the garage section of the front page and see what up there.Follow it just like it says and you will know if the r/r or stator is bad.I would be concerend about why the fuse is blowing.Is it the right fuse for that connector? 15amp? Is any wiring showing hot or melted look.Wire will get hard and brittle if they are overheating.I know how to fix the charging systm but I think the fuse thing is something different.I have just replace my stator and r/r but never had a blown fuse.About wiring the stator and r/r like I said,Yes that is the way to do it.r/r ground to battery and the SOLID RED wire to the + side

NO NO NO !!!

SOLID RED wire directly to the + side is extremely dangerous
SOLID RED wire to an inline fuse to + side is OK

If you run Red to Battery without a fuse you are asking to possibly set the whole bike on fire if anything in the charging circuit shorts to ground.

Since he has a fuse blowing, there is probably a short somewhere on the bike.
Possibly giving that short an unfused direct line to the battery is a bad idea.

I personally even think the wiring harness + is usually OK to use, since the connectors in that path are all the spade connectors, which are usually OK. If you connect into the harness, you don't need a seperate fuse, since there is one in the harness.

I agree with the rest of your post.

and the other three to the stator.There will be one wire that will come out of the harness that hooks up to the r/r.If you still have the plastic connector just cut off the connector and wire exactly like it was, matching the color of the wires up without the connector.

[tconroy]

Sorry, I just thought that everyone knows you have to have an inline fuse to protect your circuit.Im glad you added that.Next time I will be more specific!!!!