Increasingly high idle from cold start...

[JackPanzer]

Well guys, I got my leaking problem fixed...now I got another one stumping me. Whenever I rode my bike around yesterday it seemed to run decent aside from needing carb synching. I let it rest a bit and came back to it last night and started it up, bam, high rpms amd they increased dramatically over a few seconds. Pulling the choke slowed it down then increased it again. Adjusted the butterflies to as close as I could off the bike and replaced then, turned the mixture screws until they seated and tried it again. Worked for a few seconds then the same things happened; high (3k+) idle and continually increased until I shut the bike off. Throttle cable does need lubed but it isn't sticking. I don't have money to get starting fluid until next Friday and Google is failing me. Am I just missing something simple or do I just need to bite the bullet and take it to a mechanic when I have money?

[rdmcguy]

increasing idle speed

You didn't mention if you turned the idle mixture screws back out.
sounds lean to me or air leak possibly at the manifolds or starving for fuel
spray some wd 40 on manifolds at idle and see if things change.
There are a lot of variables it could be .
Start with clean carbs,no air leaks bench synch,no snagging or sticking cables
idle screw set correctly.
One thing at a time.
Good luck

[BA80]

Does the idle increase without you moving the throttle at all or does it seem to increase a little more each time you rev it?

[JackPanzer]

Does the idle increase without you moving the throttle at all or does it seem to increase a little more each time you rev it?

It imcreases withoit me moving at all. I backed out the mixture screws quite a bit. Same thing. Nothing changed with WD-40. Gonna break 'em back down and see what I did between yesterday afternoon and last night.

[JackPanzer]

You didn't mention if you turned the idle mixture screws back out.
sounds lean to me or air leak possibly at the manifolds or starving for fuel
spray some wd 40 on manifolds at idle and see if things change.
There are a lot of variables it could be .
Start with clean carbs,no air leaks bench synch,no snagging or sticking cables
idle screw set correctly.
One thing at a time.
Good luck

Appreciate the advice. I do just need to take it slow. Just being impatient.

[BA80]

The reason I asked was I've seen throttle linkage hanging on boot clamps many times. It usually will be a throttle movement that will change the speed.

The engine speed CANNOT increase without more air being allowed into the cylinder. It can only put out what it takes in. It doesn't create it. There are only a couple places it can come from.

1: Obviously the butterfly valves in the carb throat.

2; Vacuum leaks ( boots, nipples, clamps not sealing).

A set of carbs not properly, or at least closely, synced will act that way.

[JackPanzer]

The reason I asked was I've seen throttle linkage hanging on boot clamps many times. It usually will be a throttle movement that will change the speed.

The engine speed CANNOT increase without more air being allowed into the cylinder. It can only put out what it takes in. It doesn't create it. There are only a couple places it can come from.

1: Obviously the butterfly valves in the carb throat.

2; Vacuum leaks ( boots, nipples, clamps not sealing).

A set of carbs not properly, or at least closely, synced will act that way.

I'm checking the boots after a quick run for a burger. I'll be bench synching as best I can whilst I do that. But unfortunately neighbours complaining about noise. Too late to start it up again tonight. Will let you know how it progresses. Thank you again.

[BA80]

http://www.xs11.com/forum/showthread.php?t=36021

[JackPanzer]

http://www.xs11.com/forum/showthread.php?t=36021

Haha, that'sthe method I used. Split the first hole down the middle.

[BA80]

Doesn't it make any difference if you back the idle screw down?

I know when I start my bike up I use the throttle lock to keep the thing running (without the choke) while it warms up because it won't idle cold. As it warms up, if I'm not there to slow it down, it'll gradually increase to 3500 - 4000 RPMs.

I don't like using the choke because it kills plugs FAST.

[JackPanzer]

Well....I have found one issue.

[BA80]

Well....I have found one issue.

Your picture didn't show and I can't pull it up.

[JackPanzer]

Your picture didn't show and I can't pull it up.

http://imgur.com/yCXxJdV

Sorry about that.

[JackPanzer]

Doesn't it make any difference if you back the idle screw down?

I know when I start my bike up I use the throttle lock to keep the thing running (without the choke) while it warms up because it won't idle cold. As it warms up, if I'm not there to slow it down, it'll gradually increase to 3500 - 4000 RPMs.

I don't like using the choke because it kills plugs FAST.

It's a huge increase in a short amount of time. It's acting like I'm pegging the throttle. Many k's of rpms increase. I can only turn the bike on for a few seconds at a time.

[BA80]

Not exactly sure what your trying to show here. If your host has an IMG code, use that.