Voltage drops when the bike revs

I am having a charging problem with my bike. It charges OK from my charger but when I ride it, it slowly reduces the charge.

I tested everything at the weekend using some troubleshooting guide from Electrosport (or something like that) that I downloaded from a post on this forum. Everything seemed OK the first time around but I now doubt that I did it right.

This is cos after it all seemed to check out it STILL didnt charge when riding. So I put a new earth lead from the RR black cable to the battery directly and an extra Battery Neg to Frame cable.

When the bike is idling it is about 13.5v when revved to 5k rpm it drops to about 12.5v

Any ideas?

Thanks

[fizzwheel]

Theres some stuff in this thread about checking the charging circuit.

http://forums.sv650.org/showthread.php?t=103259

Hope thats relevant to your problem.

Cheers Fizz. I had already gone through that thread and its because of that thread that I put the extra earth leads on.

Sounds like the regulator rectifier is on out...

'common' problem,

[Biker Biggles]

Have you checked the alternator output?The three yellow wires that go into the reg/rec can all be checked for more or less equal outputs of (from memory)about 70 volts ac.If one is down you have an alternator fault.

[johnnyrod]

Yep make sure you have the r/r disconnected when you do. About 50V+ at 4000rpm is good

Originally Posted by Colby

When the bike is idling it is about 13.5v when revved to 5k rpm it drops to about 12.5v

I have just fixed this very problem on my sons 99 curvey. I ended up putting a wire directly between the red lead from the regulator and the positive terminal on the battery. All is well now

Originally Posted by lookskyward1

I have just fixed this very problem on my sons 99 curvey. I ended up putting a wire directly between the red lead from the regulator and the positive terminal on the battery. All is well now

Indeed, that is the next step. He has done the earth side, so its time to get positive on its a55!!

I think the weak spot on the red run is the starter relay/fuse thingy ... it is exposed to muck from the wheel and the metal bit inside that connects the terminal to the fuse corrodes badly ... I had one that finally corroded totally away!!!

Do remember if you do a red run that there will then be no fuse in the line. I suggest you try it out like this then fit an in-line fuse!

Originally Posted by Blue_SV650S

Do remember if you do a red run that there will then be no fuse in the line. I suggest you try it out like this then fit an in-line fuse!

Thanks Blue, will do!

Def sounds like the reg/rec to me. Its simply not doing its job.