Carb Gremlins!!

[scottychop]

Hey all,

Trying to run a Jardine full system on my GS500 and having a really hard time getting things to run right. I have the hanging idle problem, sometimes complete runaway idle (continues to build revs). I can start the bike up fine and it idles, but as soon as I give it ANY gas, the revs go nuts.

I thought it might be a vacuum leak, but found none using ether. Could be a lean condition, but then I checked the plugs and they were black and oily (new plugs never been on the road). Rich??

Now I am completely baffled. K&N filter, Jardine system, rejetted correctly.

[Ranger]

It is an air leak I'm pretty sure.

Are the intake boots newish with new o ring and are all the clamps on perfectly with proper sealing?

[scottychop]

New boots and o rings. I did not replace the clamps. I thought air leak too, but it's running super rich!??

[Ranger]

Just make sure they're clamping in the groove and are fully seated. Not sure what's going on, what if you do grab the throttle, any black smoke coming out of the exhaust?

[scottychop]

No smoke, but an occasional backfire. I turned down the mixture screws a bit and it seems to be ok. I am spraying liberal amounts of starter fluid around the boots with no idle change whatsoever. I also sprayed around the K&N with similar results.

[Ranger]

Spraying starter fluid around the carbs with the engine running is a very bad idea. WD40 is a better choice but won't always change the idle even if there is a leak.

[scottychop]

huh. I've always used starting fluid (ether).

[Ranger]

Think about what would happen if a good amount of ether was sucked into an engine that's already running with spark and combustion from ether and fuel.

Personally I and I'm sure many people here would never use it.

Just reseat your carbs and check the clamps for now, also are you sure your float height is correct?