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MG MGA - Fuel Over-Flow

Hi, i had this past weekend a severe Fuel overflow while starting my coupe, (probaly because it's red) the car started fine but i soon heard fuel dripping so i stopped the car. I tried to knock gently on the fuel bowls to see if the float were stucked with no success then restarted the car with the same result, just more fuel. The pump does'nt stop pumping..I have dismantle et reassemble Both fuel bowl and did not see anything wrong. (worked fine the day befor!!!)

Any suggestions ???

Thanks,

Jean Marc
Jean Marc

Jean, I've had this happen. Sometimes the float adjustment is such that if the bowl level gets low - the float will drop far enough that the needle valve will bind and not return to the closed position when the level rises (holding the float down and allowing gas to flow through the overflows). When bound like this, tapping doesn't seem to work. Take the top of the bowl off, make sure there's a good level of gas - make sure the float and valve are in the "up" (closed) position and replace the bowl cover without allowing them to drop far enough to bind. Otherwise the needle valve seat is bad. The ball type gross jets eliminate this problem. Good luck,
Phil
The Other MG Brother - Phil White

Jean - You could have had a pice of dirt stuck in the needle valves. Was it both carbs that were overflowing or just one? One of the things I have observed on our TD carbs, which have the same float/float lever arrangement as onthe MGAs, is that if the fuel level in the float chambers gets too low (as from sitting for long periods of time), the floats drop far enough that the float leveris at an acute angle and the needle valve will jam against the lever instead of being lifted by it. This can be cured by modifying the lever so that there is a float (lever) drop adjustment available to preclude this situation. I have some pictures of how to do this if you will send me your e-mail address. Good luck - Dave
David DuBois

Thanks, for the answers, i belive only one carb is having that problem, the front one. Both Bowl were full when i dismantle them, seem that nothing is preventing the front one to overflow. i have checked the needle of that one and i cant figure out what is wrong with it, I have tried to play with the lever upright but i think i did worst.

Jean Marc
Jean Marc

Jean,
Check to be sure the vent pipe isn't blocked.
Doug
D Sjostrom

Jean

I would put my money on a perforated float. Have you extracted the float from the bowl and given it a shake?

Steve
Steve Gyles

And I would put my money on Steve, because he probably has it right. It doesn't take more than a tiny pinhole. Air in the float expands when the engine is hot, and is forced out thru the hole. When it cools down, a vacuum is created and will suck fuel in thru the tiniest hole.
jeff schultz

Steve and Jeff are the winners !!! Last evening i dismantle again the front Bowl and found the float completly at the bottom, not floating anymore !!! I guess it was slowly sinking before i had the problem.

I have located a new set and will replace both of them tonight.

Thanks,

Jean Marc
Jean Marc

Jean

The float is repairable. I mended mine by drilling the perforation to a larger diameter, then drilling a second 'air'hole. Shook all the fuel out and re soldered. Still working fine 2 years on.

That's 2 I have got right this month - rarity!

Steve
Steve Gyles

This thread was discussed between 15/08/2005 and 16/08/2005

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