Flathead 239 still hard to start after much work...

[rjlester]

Originally Posted by kurt v

Did you change the power valve ?

I didn't change it, I do have another one in a used carb, I could try that. What kind of symptoms do you get from a failed power valve? I haven't had a bad one before.

[rockfla]

When you rebuilt your carburetor, did your butterfly shaft have wear in it??? Did you check that as well as the above mentioned "power valve"??

[rjlester]

Originally Posted by rockfla

When you rebuilt your carburetor, did your butterfly shaft have wear in it??? Did you check that as well as the above mentioned "power valve"??

If I turn the mixture screws all the way in, the engine will stall. From what I understand, if it stays running the power valve is blown.

There is a very small bit of wear in the shaft, I've had much worse wear in other carbs that worked ok. That being said, I do have another throttle body I could try, although it has a similar amount of wear.

Sometime in the next month, I will be purchasing a complete 54 Ford parts car from a guy I know, but I won't have access to it for quite a while. I know the carb is on it, would be good to have a complete carb to compare to...

[rockfla]

You stated in the first post " I've tried to adjust the mixture screws, when you turn them in, you can find the spot when it starts to sputter, but when turning them out there is no point that it sputters until they almost come out of the threads."

IT should also effect how it runs after a certain point of backing them out AS WELL.....You are saying "it doesn't"!!!


You have also stated "When I cup my hand over the carb, the suction is REALLY strong now. Cupping my hand over it still smooths out the idle. Strange"

Which, to me, says, IF I limit the air entering the carburetor, the engine runs better......SO.....YOU are drawing a vacuum "somewhere" it should not be.....ALSO the first statement above says that the idle adjustment screws are NOT performing AS THEY SHOULD which ALSO tells me you are drawing a vacuum where you should not be. ALL this tells me, even though you rebuilt your carburetor, IT still is not functioning AS IT SHOULD. One would think THAT, IF you are sucking MORE AIR than FUEL, that, in my mind, tells me IT COULD be, at minimum, a contributing factor IN your hard start issue!!!! Call me crazy BUT there are four things needed for an engine to run.....Compression - which you have stated you have pretty good readings all in all, Spark - as you do have it running and Idling, Air - you are still breathing where you are typing SO you have air, Fuel - which you are getting under "most" conditions.....BUT NOT ALL!!!!

Hence, my advice to send your carburetor to CharlieNY, who is "THE MAN" when it comes to carburetors......He test runs them BEFORE he sends them back to you!!! The last one I sent, I didn't even have to adjust the idle....He hit it dead on - plug and play!!!!! It is worth the "insurance" and peace of mind IMO, to have someone like Charlie (who knows your carburetor inside and out, sideways and upside down) and his work and KNOWING its done right, running right and not having a care in the world as far as that piece of the puzzle is concerned!!!!! AND get the proper fitting POWER VALVE too!!!