1984 gs550l high idle speed

[tuckomf]

Hello everyone. I've been visiting the forum for a few weeks now, ever since I bought my gs550 from my brother-in-law. I decided to wait to post until I reached my wits' end, which happened about 4 minutes ago. It seems to be a common story on these boards - the bike had been sitting for a couple of years, the previous owner neglected it, and now the problems arise. I've thoroughly cleaned every individual part of the carburetor and flushed the gas tank, which brought me from the "rough idle / only runs on choke" thing to my new problem. It starts on the first try, but instantly jumps to about 5k rpm's. I've turned back the pilot air screw, drilled out the pilot screw plugs and adjusted those to about a half turn out, put some slack in the throttle cable, checked for air leaks, and nothing seems to work. According to the manual on BikeCliff's site (Probably the most helpful and organized site I've seen, by the way. Like a well kept garage in binary code) I should let the bike idle at 2000 rpms for 10 minutes and then adjust the stop screw. If I could bring it down to 2k, I'd be ecstatic! So I beseech thee, oh wise forum, please point out what I'm missing here!

Tuck

 

[tkent02]

High idle is usually caused by some form of air leak, it can also result from a carburetors being very much out of synch, so that even if the throttle is completely closed, some of the cylinders are open far enough to raise the idle way up.

I would go through the valve adjustments, as that can screw up everything else, then synch the carbs and adjust them properly.

 

[tuckomf]

I don't know if this will help with the diagnosis, but after I kill the engine, white smoke comes out of the pipes like a mofo. I do have seafoam in the gas tank also, just for cleanliness' sake. Would that make such a significant difference? It was running, albeit roughly, before I cleaned the tank and carb, so it seems to be more of a fuel thing than anything.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. truckomf,

Even though you've seen my site, you still get the "mega-welcome". I just can't help myself.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Now, take no shortcuts when going through the maintenance lists. Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[jtjastal]

I agree with tkent. I have an '83 550L that had a similar issue. I found that my airbox was warped from the PO overtightening the boot clamps. Here's my post on a fix I came up with:
http://www.thegsresources.com/_forum/showthread.php?t=154484

Make sure your boots to and from the carb are not cracked and are sealed to the carbs well also. Good luck. Hope this helps...

 

[tuckomf]

Facepalm.

The boots between the carbs and airbox line up on top. The bottom isn't lined up. I'm at work right now. When I get home I'll try taking everything off and lining it all up properly. Hopefully that's the problem. Then I can ride around town saying "DERRRR!" to everyone I meet.

 

[tuckomf]

No luck. I took the boots off, carefully lined up all the lines, sealed them up nice, and fired her up. She's down to about 3500 like that, but still loud as all get out. It's gotta be something I overlooked. My other thought is - I cleared the pilot jets with a guitar string, and I was very careful not to scratch anything. Even so, could I have screwed something up in those enough to cause this problem? Are new jets in order?

The other thing is that I put a new vacuum line on, and made it long enough so I'd have room to attach it with the fuel tank lifted, rather than squeezing my gorilla paws up under the gas tank. It's about 6 inches longer than the old one.

 

[tuckomf]

Update - I'm going with an air leak somewhere. Just on a larch, I held a handful of paper towels over the air box intake while it was running. Everything immediately tamed down to about 1300 rpm, and the exhaust looked more normal. I also noticed a drop of gas about once every two seconds from around the float bowl, so maybe therein lies the problem. I'm going to pull the carb for the 7th time in 2 weeks. While I'm in there, I'm going to check the o-rings on the intake.

 

[1_v8_merc]

I'd say airleak, very easy to overlook.

I've sprayed around all my carb boots and never got the RPM's to jump, indicating there wasn't any air leaks.

10 minutes later, I noticed a few clamps weren't quite tight enough.
After I tightened them down a little bit, the bike instantly ran better, RPM's dropped as they should, no sticky throttle.
A lot of times, you could swear everything is airtight, and then you realize the smallest gap on planet earth is causing an air leak anyways!

 

[tuckomf]

It's alive.

IT'S ALIIIIIIIIIIIIIIIIIVE!

O-rings between the carb boot / intake area were flatter than flat.

It lives. Thanks to everyone for the suggestions!

-tuck