Weber carb problems

[ClemsonCruiser]

Okay so I went out to drive my 40 today and cranked it up everything was fine; idled perfect, but once i got going down the road I began to hear a large poping noise coming from the engine. So i pulled over and it turns out it is my carb. and it is backfiring/ spitting fuel vapor out of the top of the carb. under full throttle. It does not do this at idle only under throttle. The engine has been running fine without any issues and it still cranks right up and runs good, it just back fires/spits under accleration. Anyone ideas on what is going on is appreciated...............

JP

 

[treerootCO]

Timing or maybe you flattened some exhaust lobes on the cam. Redline isn't too high on an F/2F. Been there done that on a 350 Chevy

 

[ClemsonCruiser]

no the timing is fine, but flattening the exhaust lobes is possible, when I was wheeling sunday the throttle cable got get stuck for a few seconds and I have never heard the little 2f scream so hard, but after that happened I wheeled for a couple more hours with no problems and drove the 30 miles home and no probs at all. Then it sat for three days and now this is happening............. So I amssume if I had flattened the lobes it would have had an immediate affect???? Thanks for the help

 

[treerootCO]

I really hope the cam is fine...just throwing that out there as a worse case. Only way to tell is pull the valve cover and see if all the magic works. If they don't move, something is broken. If you have a tach, you can hold the rpms steady as see if it dips at a regular interval.

 

[tobydog]

Cam problems doubtful weber problems almost a cinch. Its a great racing carb and for somone who loves to adjust on one constsntly otherwise get a non usa assan or however you spell it.

 

[toddslater]

Check your fuel filter and make sure you getting fuel to it. If/when in doubt put a fuel pressure gauge in line...if and you should be running a fuel pressure reg, it should be no more than 3 psi...constant. I'd look hear first to make sure your getting the delivery it needs to see.

 

[73lndcrsr]

Check your fuel pump as well. I have had very similar symptoms that ened up being the fuel pump. It would idle all day long, but as soon as I put a load on it, it just could not keep up.

 

[ClemsonCruiser]

I appreciate all the info guys, I am not running a fuel pressure regulator, so that might be it. Of course I haven't been running one for like a year now and had no problems so who know, bu the will be the first thing I will check. Then I will move to the fuel pump, thanks again guys.....

 

[ken_79-fj40]

I run a regulator with my weber, and I did at one time have a similiar problem to yours. A regulator is a good idea, but likely not your problem. It would start and idle fine, but drive down the road and it would lose power, cough and puke, etc. Turned out the crappy aftermarket fuel pump wasn't putting out enough fuel. Stuck the 25 year old (i think) pump on there, been fine ever since.

 

[Magoo]

being that i dont promote weber carbs,cause a good asian carb is all you will EVER need,here is what i would do.unbolt it and throw it as hard as you can at the nearest jeep.but thats just me.
shawn

 

[CruisinTiger]

hey jp I had the same problem before you guys came over and adjusted the timing. are all the wirers on your plugs attached good. other than that beats me.

Chuck