Wouldn't start, then trouble idling

[flyingace]

Petcock diaphragm is a-okay! No gas in the mouth.

Took her out to start her. Petcock on "ON" and full choke with no throttle, she started immediately up. Idled at around 1100 for a second or two, then steadily climbed to around 3200rpms. After that for a second, idle started dropping again and would threaten to stall if I didn't "blip" the throttle and actually hold it a bit open, but just the smallest bit. Just enough to put a bit of pressure on the throttle.

After only about three minutes, she would idle without any choke at 1000rpms. It seemed like it was staggering a little bit, as the handlebars were vibrating enough to shake the right mirror to rattling a bit. But still, I'm very happy.

I wish I had heard other GS engines besides this one. I can't tell if it sounds good or not. There seems to be a "hissing" coming from the top end of the engine. Not sure if this is normal or not. Also sounds like there's a slight, low rattle as well. It's not high-pitched. This seems a little futile without you guys hearing it as well. I'm just reluctant to take it to a mechanic who knows nothing about GS's.

Like I said though, I'm very happy. It's getting better everyday, and I haven't even ridden it yet this year. Next is cleaning all the connections and testing the electrical system. I also read something about cleaning the oil strainer in the pan. Add it to the list,...

Thanks guys,
Mike

This all sounds quite normal for a cold engine. I have to keep the choke on for at least 4-5 minutes before it will idle. If it dies after that, consider turning the idle adj screw up just a little - there's nothing wrong with an 1100 RPM idle. The hissing - has to be air intake. Look for obvious leaks and try the water mist test described in other threads.

[Billy Ricks]

Mike, it sounds like you have a pretty good intake leak. Did you try spraying any WD-40 around the manifolds yet? You may have a bad manifold or two.

[UncleMike]

This all sounds quite normal for a cold engine. I have to keep the choke on for at least 4-5 minutes before it will idle. If it dies after that, consider turning the idle adj screw up just a little - there's nothing wrong with an 1100 RPM idle. The hissing - has to be air intake. Look for obvious leaks and try the water mist test described in other threads.

Mist all around the carb boots. Anywhere else? Or just everywhere?

[Billy Ricks]

Mist all around the carb boots. Anywhere else? Or just everywhere?

Just around the manifolds. Use water if you want to since the WD-40 will make a little mess. The water should make the bike want to stall.

[UncleMike]

Nope, not a stutter or stall when misting. Tried it both when it was warming up and when it was warm. Nothing. The thing starts right up with no choke once it's warmed up, and idles beautifully.

Took her for a little ride into a parking lot down the street. Man, does she run great.

The "hissing" is def. from inside the engine, although both it and the rattle were significantly quieter once the engine was warm. I'm thinking it's normal and I'm just being too picky, too nervous?

BTW, I love the power on this thing. I swear it would wheelie if I gave her enough gas in first. I don't even think I'd have to dump the clutch.

So how long until that power isn't enough and I need to move up to liter class? I promised myself my next bike would be a moto, so I'll have to resist the urge.

[mark]

Okay, that makes sense.

When I pull the vacuum line, put it to "ON" and suck on the line, gas should or shouldn't flow? You say it should, but also say that if it does, I'll have something else to fix. Were you referring to a mouthful of gasoline, or would the petcock then have a faulty diaphragm.

Or is this whole thing a long-distance practical joke, with the goal of getting me to drink gas in retribution for the political/relgious threads?

I'm on the run for today, and so missing out on all the fun here. Sounds like its getting better.

Retribution for religious/political threads? No way. I like 'em.

[UncleMike]

I'm on the run for today, and so missing out on all the fun here. Sounds like its getting better.

Retribution for religious/political threads? No way. I like 'em.

Much. I'm just hoping that it'll still start after sitting for a couple of days.

Maybe I'll just have to make sure I don't go a day without riding.

[Billy Ricks]

Much. I'm just hoping that it'll still start after sitting for a couple of days.

Maybe I'll just have to make sure I don't go a day without riding.

If you let it sit for more than a day use the prime position on the petcock and wait about 30 seconds before you try to start it. Just remember to take it off prime.

[UncleMike]

If you let it sit for more than a day use the prime position on the petcock and wait about 30 seconds before you try to start it. Just remember to take it off prime.

Here's keeping my fingers crossed.