Cb400f idle issues

[scanderson76]

Hello all,

So my cb400f seems to shut off after running for awhile. I was at the stop light the other day and it just shut off. I am guessing I need to make an adjustment on the carbs. I did just move from an elevation of 1000 ft. to a town of about 5000ft. I am pretty sure that is screwing with something. Any help would be greatly appreciated.

 

[timeconsuming]

I too have been experiencing some idling issues lately... mainly when things heat up.

In the morning its cold (55 degrees... San Diego cold) and I ride on the freeway for about 20 minutes to work each weekday and it idles great at the few stop lights post freeway...

Then on the way home it's warmed up outside and by the time I get home I can feel like engine heat between my legs a bit... At the few stop signs before my house I've experienced some failing. Basically idle revs high for a minute and then drops low before sputtering out. Starts right back up with one embarrassing kick, idles high, and requires throttle periodically to keep from cutting out again.

Overheating issue? Any guesses?

Also sorry for thread hijack! Wish I had more tips but I'm assuming you're on point with your thought of elevation pressure issues and carb readjustment

 

[swan]

Thinner air makes your carbs run richer, so you will need to consider a leaner idle jet, lowering your needles one notch and possibly a smaller main jet.

 

[scanderson76]

Thinner air makes your carbs run richer, so you will need to consider a leaner idle jet, lowering your needles one notch and possibly a smaller main jet.

Thanks swan...I was thinking of lowering the main jet to start. It seems like I have a slight flat spot at 7k like its struggling for air...I adjusted all my air/fuel mixture screws to the factory specs. Do you think that will help too?