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Author Topic:   KP!!!!! PLEASE HELP
posted August 26, 2004 01:30 PM
Car started hesitating in the corners (fluttering).
it's a Methanol 4150 Carb. I replaced the Floats, needles and seats, Power Valves, and fuel pump (since I knew the spring was broken in it).It also has 97 Jets in it.
Now when we start the motor up, Methanol POURS out of the exhaust unless we move the front float as low as it will go. Borrowed another Carb, and it quit doing it. First we thought maybe I got the wrong fuel pump( to high PSI),we don't have a pressure gauge, but as I said it's fine with a borrowed Carb.
Any opinions on what I changed that may have caused this?

posted August 26, 2004 02:30 PM
Droper23. We had the same problem with one of our gas carbs. Couple things were wrong. We found trash stuck in the needle (real small) that would keep it from closing off. Plus we found that our float was to high in relation with the needle and could not get the fulcrum arm (float arm) perpendicular to the needle to get good pressure for closing the seat. We bent the float down slightly and were not spewing fuel any more. One other thought would be you have a faulty power valve that is draining the bowl into the intake. Just a thought and recap of our dilemma.

posted August 26, 2004 08:02 PM
Sorry about missing this one earlier.
Like in the other post, NEVER use Viton rubber needle/seat assy's in alky carbs. Firstly, they don't flow enough since you need about a .150" size for alky, and the alky will eventually eat away at the needle tip.

Check that your float hasn't become crushed from a backfire or is taking on alky and sinking.
Next, check that the gaskets are straight on the power valve and there isn't a leak there.
Next, if you're VERY sure you don't have either a faulty needle/seat or trash in there, then another place excess fuel can come from is a torn or missing O-ring on the seat assy itself. And if a piece of trash did come thru there, there's a slight chance it could've "dented" the seat area enough that it'll never seal up again, which will cause the symptom you're seeing.

Another thing that can do it one or both idle feed restrictions could have fallen out (not at all likely, but ya never know).
This won't allow fuel to just "puddle" or literally drown the motor, it'll mainly cause a very overly rich idle condition.
Another thing that can cause your condition is if someone put on HP metering blocks and didn't plug off the one little vacuum hole in the main body that lines up with the idle feed circuit. That vacuum hole is for the timed spark vac port on the sides of OEM metering blocks (follow that circuit and find where that vac hole is and plug it off if you're using HP metering blocks).

There's lots more, but let me know if any of this initial stuff helps, and we'll take it from there.

Again, sorry for the delay in replying. I've been overwhelmed again in shop work.


[This message has been edited by KPLugnut (edited August 26, 2004).]

posted August 27, 2004 05:03 PM
Thx KP
I just broke down and bought a new 4150.
Less headaches.

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