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Carbs spitting fuel out of intake. Help?

DoorBuster2

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Title basically says it all; I've been rebuilding my 1978 CB750A for the past three months, and I think it's finally in a shape to run. I rebuilt the carbs with the carb rebuild kits, and cleaned everything, and replaced all screws. I put it in, hopeful it would start, and as it was cranking over with choke fuel started to spit out of the carb intakes. Without choke, it doesn't spray as much, but with the choke or throttle fully opened it sprays a ton of fuel (fuel comes out where the airbox connects).

I don't think its a stuck fuel pin or float because the day prior I had reset the float to its correct height (something like 0.571 for the A model) and made sure everything was moving.

Any thoughts on what could be wrong?
 
Yeah, float needles were all cleaned. and seem to be sealing properly. I just did a little test to see if even provided excess fuel, would it leak out the top (if the floats were letting in too much and causing to overflow) but they didn't; suggesting that they are sealing and floating well enough.

Another person brought up I might have reversed the cam shaft timings and whatnot, but I followed Hackaweek and Peter Andersons build guides to a T. They thought that if I installed them wrong, then they are blowing air out of the intake and suck it in from the exhaust, but like all of Honda's bikes, a lot of those parts are only designed to go one way. I'm not sure if I'm really retarded and somehow managed to fuck it up, but pulling the engine is another task that I'd rather not do again, but looks like I have no choice to double check it.

Thoughts on anything else that might be causing the issue? Just to try and spare me from a days worth of engine pulls.
 
Just to be 110% clear, NOBODY said anything about anybody as far as a person being retarded. I suggested the cam timing might be retarded. I assure you too that not only Honda but ALL engines on earth can generally flow backwards if something is not right. Thinking not is a huge error. They do it all over the place in small amounts even when running right. Doesn't matter anyway as retarded timing does NOT make the flow go backwards per se, the effect comes from slow timing burning the mixture slowly to still be burning at overlap to then go backwards out the carb. Two somewhat different things. Suck in from the exhaust? They ALL do it, it is part of the physics to do so. You don't understand engines if you think otherwise.

I have built so many engines for both car and bike I cannot count including some making thousands of horsepower. Just so you know.

The fuel could simply be overflowing from stuck needles if they use ethanol in your local fuel, I've seen it many times; if bike gets left 2-3 days it does it until needles get wet enough to come unstuck, the ethanol does it. Cheap crap Chinese needles can do it too, they use substandard rubber needle tips and the needles then stick again to ethanol.
 
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