Sudden stalls after servicing

[Nighthawk016]

okay, so I'm very surprised no one mentioned this. There are 2 petcocks on the GS500. One directly on the bottom of the tank and the one that says on and reserve. The one on the bottom of the tank can not be fully turned to open; if it is it will starve the bike of fuel causing intermittent issues like you're mentioning. IIRC the petcock needs to be exactly 90 degrees from closed, any farther and you aren't getting full flow.

[smokestack]

The one on the bottom of the tank can not be fully turned to open; if it is it will starve the bike of fuel causing intermittent issues like you're mentioning. IIRC the petcock needs to be exactly 90 degrees from closed, any farther and you aren't getting full flow.

Not sure what you mean. You're saying having the tank petcock turned fully open will cause fuel starvation issues? I've been turning it as close to 90 degrees from off as I can.

[jdoorn14]

It's worded funny, but I think Nighthawk is saying it's possible for the petcock to be not quite at 90 degrees from off, which could cause fuel starvation.

[Janx101]

You can turn it past 90degrees and start to close it again!

[jdoorn14]

This is true. When you consider that 90 and 270 degrees from off are full on, and 0 and 180 degrees are full off, anything between is partially off (or partially on if you're an optimist).

[jeZZa]

i had similar problems with my gs, replaced the coils, leads, caps, plugs, carbs and ignition module and pickups and still had the same fault.... eventuly traced it to a iffy wire (it had broken off and would randomly lose contact) in the ignition plug and a very dodgy earth..... check your wiring... i wish id started there

[Nighthawk016]

You can turn it past 90degrees and start to close it again!

This exactly.


If you turn this petcock passed ON it will cause fuel starvation issues.

[smokestack]

Found some metal flakes in the oil   

https://imgur.com/ahYL1e6 (the magnet head is 8-10mm wide)

[Big Rich]

I wouldn't worry about those tiny little flakes......

Are they good? Of course not. But that's not enough that I'd be worried at all.

[smokestack]

Nice to hear. Anything to do about it? Quick history: bought at about 24k miles, I've only been able to put about 750 miles on it since I bought it 1.5 years ago. Haven't changed the oil until now (my fault). Was probably running about 100 miles about a quart low. Unknown previous owner. Had carbs rebuilt by a mechanic about 50 miles ago and it's been running very lean and hot, likely burnt out my signal generator coil.

The plan is to put some cheap Castrol motorcycle oil in for 50-100 miles then put in full synthetic. I read that the quick, back-to-back oil change is a good way to flush. Will cut open the oil filter to inspect. Also plan on taping off half the airbox intake to see if it helps richen the mixture then maybe try rejetting. The mechanic probably put in the stock jet size (I should call her though..). Going to try spraying starter fluid on the carb->engine intakes after it's put back together to check for leaks.