idle won't drop

Idle takes 15 seconds to almost a minute to drop down to normal after stopping. 2003 klx400sr mikuni carb.

Clean the carb , replace the pilot jet .

Try reducing your idle speed.

Also check your valve clearance.

I would first check that the idle speed isn't set too high and/or adjust fuel mixture screw richer (usually when the pilot circuit is lean the RPMs will hang when reducing the throttle to idle).  Now if you find the idle speed doesn't change much and/or the fuel mixture screw doesn't help or you need to adjust it a lot… then you probably should remove the carb and throughly clean it (paying careful attention to the pilot circuit).

 

Idle takes 15 seconds to almost a minute to drop down to normal after stopping. 2003 klx400sr mikuni carb.

 

Do you have the dyno jet slide spring? if so you might try the stock spring, I had an intermttant high idle issue with dyno jet slide spring weaking after many thousands of miles.

 

 

Do you have the dyno jet slide spring? if so you might try the stock spring, I had an intermttant high idle issue with dyno jet slide spring weaking after many thousands of miles.

No the bike only has 2500 miles on it.

I would first check that the idle speed isn't set too high and/or adjust fuel mixture screw richer (usually when the pilot circuit is lean the RPMs will hang when reducing the throttle to idle).  Now if you find the idle speed doesn't change much and/or the fuel mixture screw doesn't help or you need to adjust it a lot… then you probably should remove the carb and throughly clean it (paying careful attention to the pilot circuit).

I think I'll try cleaning the carb. The idle is fine once it drops down. It does also have a slight miss when you just crack the throttle but is smooth through the rest. Could all be related thanks.

 

No the bike only has 2500 miles on it.

 

so you dont have a dyno jet or any aftermarket slide spring, and completely stock?

If so then I'd say you might be just leaner than normal, and it is getting colder. Have you even drilled out the plug to access your fuel screw? Its really a must have adjustment.

stock comes pretty lean on the idle circuit

 

 

so you dont have a dyno jet or any aftermarket slide spring, and completely stock?

If so then I'd say you might be just leaner than normal, and it is getting colder. Have you even drilled out the plug to access your fuel screw? Its really a must have adjustment.

stock comes pretty lean on the idle circuit

Bone stock. I am going to take the carb off and clean it.  Pop that cap off so I have adjustment. Thanks for the info.

 i had the choke out on my bike and couldnt figure out why it wasnt engine braking. i had adjusted the idle to compensate for it. it seems like i forgot everything after not riding for a few weeks...

Edited by jawknee21

while cleaning carb ..... clean/lube/replace throttle cables.... one could be sticking.

while cleaning carb ..... clean/lube/replace throttle cables.... one could be sticking.

Great thought I'll do that!

Yeah sounds more to me like throttle cable, not carb. Does throttle spring back to closed when you let go of it?

Yeah sounds more to me like throttle cable, not carb. Does throttle spring back to closed when you let go of it?

Sounds and feels like it does.

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