Carb Stumble

[a-dub]

I did the shotgun recently because the idle circuits were clogged. Problem is now gone, but I have noticed i get popping/stumble out the exhaust during high rpm shift from 1st to 2nd. It stumbles for half a second or so and then continues to pull hard. I roll off the throttle when I shift. Could this be an idle mixture adjustment issue or something else?

 

[lightninggrant]

Have you read this article.
http://www.vmaxforum.net/showthread.php?t=2468

Also did you sync the carbs after putting them back on.

Grant

 

[a-dub]

Did not sync the carbs. I did check for vac leaks, no vac leaks.

 

[jfeagins]

You might still have some poo down in there someplace.

After you synch the carbs, you might try running a tank of gas with a couple/three ounces of the almighty Sea Foam additive and see if your blurp clears up.

Stuff works wonders and saves carb teardowns routinely.

 

[a-dub]

Its had a lot of seafoam. Tried adjusting things tonight and now its running pig rich, way down on power.

 

[a-dub]

So i tore into it today, the main jet air bleed on the rear right side carb is dumping fuel into the engine. I'm guessing this means the float is stuck?

 

[naughtyG]

So i tore into it today, the main jet air bleed on the rear right side carb is dumping fuel into the engine. I'm guessing this means the float is stuck?

It's possible, but the most likely cause is crap in your fuel (and therefore in fuel bowl) that gets stuck between the needle valve and its seat, preventing it from sealing. If there's a lot of crap, it can even prevent the whole needle valve from moving freely, which has the same result.

Of course, it is also possible for the rubber of the needle valve to be worn out and in need of replacement, but more rare.

Either way, first you dump the gas into a clear or white container by opening the drain screws, and if you find dirt in there you need to take the carbs off to break the rack up and get into the fuel bowls.