Screaming startup

[willstyle]

On my 97 KDX200 when I start it up it wants to scream and it scares the crap out of me when the bike is cold. After it warms up it settles down. That is the confusing part. I dont think that it is my throttle cable binding. One thing that I thought is maybe the bowl gasket for the carb may be shot after changing the jets so many times and not sealing? I cant figure it out. The one thing I havent done is spray starting fluid around to check for air leaks. I searched the posts and didnt really find anything similar. If it always overrevved it would be one thing, but it stops when it is warmed up. What do you guys think?

Will

 

[CMcCarthy]

My '94 does the same thing when you start it using the choke. I usually just pull the choke out about half way, and it starts fine then.

 

[canyncarvr]

Made worse by being a bit lean on the pilot, this isn't uncommon.

You can either make a 'pre-start' air screw adjustment (turn it in say 1/2 turn or so), or use the kill button as a regulator. Re-adjust the AS as required after warmup.

I thought the kill switch idea would load the thing up so bad I'd be eating plugs on a regular basis. That hasn't happened yet...and I've been doing the intermittent kill-switch method to tame the cold-choke 'overrev' for awhle.

Can't say I know why this happens in the first place. Maybe it takes awhile for the case to become effective in transferring fuel in a useable form (vapor is good!).

Of course...a leak would do it, too.

CM:
How do you pull your choke out '1/2 way'? It doesn't latch there.

Of course...my choke doesn't latch ANYwhere...but that's another issue :(

 

[Jim Crenca]

CC
I thought my cold run away idle problem cured itself but it came back yesterday. I'm afraid to touch jetting aaagain; think I'll start using your kill button idea. My 94 did not do this for at least 1 year; why start know; possibly C-12 or hot weather?

 

[canyncarvr]

1. While I'm sure there is an exact and correct answer, I don't know what it is. The 'why start now' fits my situation, too.

2.RE: kill switch. It's not my idea. I hadn't considered it, and like I said, if I HAD, I'd'a thought it would cause a loading problem.

Jayhawk is the one the credit goes to. At least, I heard it from him.

So...when your bike blows up the 5th time you hit the switch, call him! ;)

 

[CMcCarthy]

CC,
I only use the choke for 30-45 seconds, so I just hold it halfway up manually. It works quite well.

 

[Jim Crenca]

One day later; no run away idle. Go figure.

 

[jboomer]

My KX does this too ('01). Once the bike starts, I quickly turn the choke off for a few seconds, then turn it back on and it doesn't do it anymore. Weird...

 

[dan00bhave]

I have a 87 kdx 200, mine has always done that to. I usually choke it first, kick it once, shut choke off when it starts then the screaming dies down. I think it's just a common trate. If you find out anything different let me know.
I don't let it bother me. The neighbors hate it though..lol :aj:

 

[JasonWho]

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[jboomer]

5 minutes or so. Not too long. It's usually loaded up too much to allow it to sit for any amount of time. I've got jets in the mail to reduce some of the richness. Can you believe the bike shop here doesn't carry jets in stock? Geez!