GS550L Starter Issues

[Guest]

Hello all - I'm having some problems with the starter circuit on a 1985 GS550L.

Here is what I have determined:
1)Fully charged battery.
2)Starter solenoid clicks and outputs 12v
3)Wiring to the starter motor also outputs 12v when starter button and clutch are held
4)Removed starter motor from bike and directly jumped to battery, spins like a drunken sailor.
5) Side Stand light remains illuminated regardless of stand position (normal?)

I have been able to crank the engine a couple of times, but it begins slowly, and picks up momentum - enough for me to compression test cyl 4 - 110PSi.
most of the time it just clicks the solenoid.

Any thoughts? Really puzzled - it should be cranking.

[gustovh]

Check your grounds and connections.
V

[eil]

1)Fully charged battery.

Are you absolutely sure about this? How old is the battery and how have you tested it to make sure it still holds a charge? (Hint: just putting a multimeter on it won't work, a perfectly bad battery can still read 12V with no load.) One test is to try jump-starting the bike with a known-good car battery. (But do not have the car running when you do this!)

Like gustovh says, bad electrical connections seem to be the cause of most electrical problems on these bikes.

I thought I also read a thread where a starter motor was in need of rebuild and behaved like yours... spins fine in a test but not enough oomph to turn the engine. So that may be something to consider once you've got the easy stuff out of the way.

[Gorminrider]

yes, check connections, then ideas I'd do:
starter motor- don't burn it out. Because, it might not be the starting motor...just an old bike gummed up. Test to make sure you can spin the bike by hand easily with plugs out. Don't burn starter out trying to start a seized engine! because actually, the starter needs to be ok to really burn it out!

starter out of bike: Brush faults are common....bearings/bushings less so but looseness is no good...if you have the starter out, I would clean it up around the brushes anyways...then, free wheeling, can you get starter to
"buck like a bronco"? (is what I might say instead of "drunken sailor"..) by connecting the free-wheeling starter to it's proper solenoid connection and battery Negative pole ? That means solenoid + starter are probably ok .... Less common but just possibly, the brushes allow it to freewheel but are not delivering enough amperage (ie:doesn't buck like a bronco) ..see above cleanup brushes and or replace..
starter IN the bike, try: by-pass the solenoid relay by shorting across the big connections from battery+ from starter... will narrow problem down to solenoid or connections really quick but free the engine first!.... can the starter spin the engine with plugs out?
.
"sidestand light stays on" is not good. I don't have this safety so can't say, but I would expect you can disable it .

[Killer2600]

"sidestand light stays on" is not good. I don't have this safety so can't say, but I would expect you can disable it .

Actually it IS good and normal, sidestand light comes on in tandem with the oil pressure light in an attempt to better catch your attention. When the bike is running the oil pressure light will turn off and the sidestand light will function normally.

[Gorminrider]

Actually it IS good and normal, sidestand light comes on in tandem with the oil pressure light in an attempt to better catch your attention. When the bike is running the oil pressure light will turn off and the sidestand light will function normally.

but I was thinking per OP's.."regardless of stand position"? What would be the point if it didn't go off when the stand is up?