When I stopped for gas, I put the sidestand down and dismounted.  Then before I turned the bike off, I noticed the oil light start to flicker.  So for some reason the oil pressure was low.  I reved it a little, which brought the pressure back up, but then it seemed to lose pressure again.  So I turned the bike off and filled up.  Then I put the bike up on the centerstand and checked the oil, it was fine.  Actually, I've gone 1300 miles since I changed the oil and I don't think I've added any, which seems abnormal for the GS500.  Once the bike was upright again and I reved it a little, the light went away.  I watched it the whole way home and the light never came on.  When I parked on the sidestand, the light began flickering again.

Summary: Bike is at running temps, oil light comes on only when on sidestand, correct amount of oil (10-W40), 8200 miles on bike, about 60 degrees F outside

Any ideas?

I definitely would not ride anymore until the problem is rectified. It is possible the oil light sending unit is going bad, or could be pump or something else. Maybe you can hook up a gage where the oil light sending unit goes and check actual pressure. If the pressure is good, which on plain bearing engines is usually around 10-20 psi at idle hot, then I would try a new sending unit. I'd say Kerry or Srinath or one of the others may have better info for you. Good luck man. How I do adore the GS500 and this forum!!

Cernunos

I'll defer to Srinath (or one of the racing gurus) on this one.  I seem to remember him saying that the GS makes a pathetic amount of oil pressure (5 psi?), but don't quote me.

I can imagine an "oil pickup" of some kind rising above the oil level on the right side when the bike is tilted over on the sidestand.  If that's anything like how it really happens, then low pressure would be a reasonable result.

I rarely run the bike while it's on the sidestand, so I can't remember if I've seen the oil light come on in that situation or not.  But if the light NEVER comes on when the bike is vertical and the engine is running (not counting the first second or two after startup) then I would think you're good to go.

Srinath?  Bob Broussard?  dgyver?

Don't know, I still think I'd investigate this. Oil is a motor's lifeblood and I never take chances. Clymer illustrates a very good procedure for checking oil pressure on the GS. There is even a plug on the right hand side of the motor which is specifically for checking the pressure. Oil pressure at 140 F should be between 28 and 71 psi at 3000 rpm. I might understand loss of oil pressure with bike leaned over statically if the level is low, but not with proper oil level. Let us know and like Kerry says, Srinath may have other ideas. Oh one other thing...have I said how much the GS500 and this forum is loved?

Cernunos

Thanks for the responses Cernunos and Kerry

Well, I am away from my bike and my clymer this weekend, so I will have to wait until monday evening to investigate.  On one side I am not too concerned, but on the other, I definately don't want to ruin my engine.  Sounds like I will have to purchase a pressure gauge or see how much the local dealer will do it for

Any other ideas?  Srinath?(they say you should know :mrgreen: ) Or anyone else for that matter?  It just seems odd that no one else has had a problem like this, I searched.

What is your idle RPM? I have heard of folks actually adjusting it higher than the recommended 1200/min bacause they want to make sure oil pressure is good at idle.

Quote from: manofthefieldActually, I've gone 1300 miles since I changed the oil and I don't think I've added any, which seems abnormal for the GS500.

What do you want to say with that? That your GS normally uses more oil? A GS can use anything from next to nothing to a quart and more per 1000 miles, depending on the RPM range it is used in.

IF your GS normally uses more oil than you are experiencing now you could have got gas in the oil (needle valve problem in the carburetor and petcock in PRI or defective.) That might influence the ability of the pump to build up pressure with the volatile substances in the oil.

Idle RPM is 1200, I believe everything else on the bike is stock, I have no reason to believe the previous owner messed around with any settings.  But then again who knows.

I noticed that just about everyone complains about having to add oil over time, so I mentioned that my bike has used none or very little in the 1300 miles that I have had it.  I can't say whether or not it used any oil beforehand.  I smelled the dipstick and pressed the oil between my fingers and could find no traces of gasoline, but I thought I could smell a little when I stuck my nose in the oil opening.  I guess I'm saying that I'm in denial about the possibility of gas in the oil.  

I still haven't gotten the chance to read through my clymer about pressure testing, but thats probably next on the list of things to do as long as it doesnt rain anymore.

Did you try tipping the bike (carefully) the other way and seeing if the light comes on that way too?

I would be that its something wrong with the sensor or (more likly) a loose or damaged wire.  With it on its side and flickering, wiggle the wire on the sensor and trace up to the wiring harness looking for any thing obvious.