My beater FB has gone it's first 750 miles troublefree (amazingly) after being out of inspection for 4 years sitting in someones yard. Every once in a while, I'll come to a stop or I'll be in the middle of braking to a stop (with the clutch in), and the engine will quit on me. I can try to hit the gas but it just kind of... peeters out. It will always start right back up afterwards. It's most prevalent in the morning when the choke automatically pops back in.

Is this a fuel delivery issue like a fuel pump, clogged filter, etc, or should I just adjust the carb (bring the idle up, richen the mixture, etc.)?

Kev

 

Idle should be 750-800 rpm warm. It may be fuel related, could also be the decel/dashpot unit.

 

my doze the same thing
iv tryed all above
no matter what i do i couldnt get idle that low trust me iv tryed alot of things

 

Start with your timing, and make sure you have spark on the leading and that the timing is set correctly. Next, move on to idle speed adjustment. If you need to crank it up to a higher rpm to keep it running, then go ahead and do so.

Once that is done, you can play with the idle mixture setting. Turn the mixture screw in all the way (gently, don't cram it in or you will ruin the seat), then turn it out three turns. Once you are at that point, start turning it in until the idle starts to get rough. Then turn it out 1/2 turn. After you get it idling smoothly like that, then you can try reducing the idle speed back down to spec.

Run a can of Seafoam through the gas tank (mix with 1/8 tank of gas for a strong mixture), then take it out and drive it hard to clean out any carbon in the motor or gunk in the carb.

If you go through all of that, and it still stalls out on you, then you may be looking at a carb issue (time for a rebuild).

 

mine would only idle with the choke puuled, finally went through all the vacuum hoses, several times, works good now

 

i had the same problem last year - changed the fuel filter and no problems since.