Carb issues??

[benson64L]

Ive been having problems with my 79 620 for some time now. I think i got it narrowed down to the carb, it seems to be dumping alot of fuel at idle before the butterfly valve. Im not really sure how much is suppose to come out there but like i said it seems like to much. The engine idle good but as soon as it give it gas it bogs down. The ignition and valve timing is set right. can anybody help me out?

[ggzilla]

Sure, are you in seattle? Could look at it tonight.

[datzenmike]

You are likely looking at the squirt from the accelerator pump, that's normal when you pump the gas. It enriches the air mix to help transition between the idle and primary circuit. If anything it may need more.

 

If when driving in town, you slow to go around a corner in say third gear and step down on the gas as you leave and the motor just baffs and stutters on you, this is a sign that the accelerator pump isn't working.

[benson64L]

Nah im not in seattle thanks though man. I cant even drive it right now and when it did drive everything seemed fine as far as taking corners or goin up and down hills it never hesitated. I was driving home and it started to idle rough at a red light then when i went to go take off as soon as i gave it gas it bogged way down and had no power, and after that day i cant even put a load on the motor, it bogs down and dies right away.

[datzenmike]

Stock carb??? look at the fuel level glass sight in the front. Is it more or less in the middle?

 

Are the plugs sooty and dry or normal tan color? Or are they very light or even bright white? This will tell you if running rich, normal or very lean.

[benson64L]

Yeah the carb is stock, had it rebuilt about 3 months ago but thats it so far. The gas on the glass sight is just a little above half and the plugs were black and seemed to have fuel on them when i pulled them out. I also pulled the carb today and there was a good amount of fuel in the intake manifold.

[benson64L]

Im thinking that the venturi is spraying to much fuel in. When you look down the carb with a flash light its pouring quite a bit in. Like i said though im not sure how much is suppose to be flowing out. This is my first vehicle with a carb.

[ggzilla]

The most common cause of this (running fine one minute, poorly the next) is when some crud gets in the jets. If that's the cuase, Just need to rinse out the jets.

 

This happened to me three times in one year. even with new filters.

[benson64L]

A buddy of mine said that might happen. The truck sat for about a year and i didnt clean the tank before i started running it but i did put a new fuel filter in before running it. Im gonna take the carb apart tomorrow, i will check that out. thanks man

[ggzilla]

No need to take it apart. Just remove the jets (if it has bottom jets accesible from outside), rinse them and replaced. Or just remove the top of the carb and do the same. Less chance of problems if you do the minumum needed.