'57 640 won't start

Criminy I am stumped. Fuel not getting to cylinders. New spark plugs are dry after continued cranking. New carb, new intake/exhaust manifold. Recent new head & valves. Compression 110 @ 1&4, and 100 @ 2&3. Blue spark @ plugs, new points, etc. so can't be electrical. Has clean gas tank & fresh fuel. Gasoline floods out of carb when first cranking but float set okay @ a quarter of an inch. (Marvel schebler tsx580). Cranks reasonably fast (12v system). I'm pretty good at diagnostics, but this one has me stumped. Was going uphill and lost power after several hours of trouble-free use. Wouldn't restart after that.

Blue/white spark means nothing unless it will jump a 1/4 inch gap or more. Next pull the air cleaner tube off and take you hand and hold it over the carb. You should get a good suction and gas on your hand when you spin it over. Shoot it may even fire up by doing that.

Pretty much any motor with an updraft carb is going to have gas running out of the carb intake when you let off the starter if it doesn't catch in about four seconds. When it is choked it is sucking a lot of gas up into the manifold. When you let off the button Gravity is pulling a lot of it back down. Choke it longer.

Shoot it may even fire up by doing that.

hey old you ain't tryin to bypass the filters again are you, i mean shoot, shoot ????? GGGGGG.

(quoted from post at 18:12:26 05/27/15) Blue/white spark means nothing unless it will jump a 1/4 inch gap or more. Next pull the air cleaner tube off and take you hand and hold it over the carb. You should get a good suction and gas on your hand when you spin it over. Shoot it may even fire up by doing that.

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Okay thanks. Length of spark is hard to measure, but I am satisfied we're not dealing with electrical issues in this case. Fact that plugs are dry and apparently not getting gasoline is what I'm trying to focus on. I will try choking with my hand today and report results. Thank you all for your helpful feedback.

If you're convinced that you're getting good spark and not getting any fuel to the cylinders, try disconnecting the air cleaner and spray some starter fluid into the throat of the carb while the starter is spinning the engine. If you have good spark it should start and run as long as you keep spraying the starter fluid.

(quoted from post at 09:31:46 05/28/15) If you're convinced that you're getting good spark and not getting any fuel to the cylinders, try disconnecting the air cleaner and spray some starter fluid into the throat of the carb while the starter is spinning the engine. If you have good spark it should start and run as long as you keep spraying the starter fluid.

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Okay thanks for that advice. I've tried spraying starter fluid into carb directly but didn't crank engine while doing that. Also, into the head spark plug holes to no avail. I will try your method and keep spraying while cranking. Thanks again.

(quoted from post at 15:40:06 05/28/15)

(quoted from post at 09:31:46 05/28/15) If you're convinced that you're getting good spark and not getting any fuel to the cylinders, try disconnecting the air cleaner and spray some starter fluid into the throat of the carb while the starter is spinning the engine. If you have good spark it should start and run as long as you keep spraying the starter fluid.

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Okay thanks for that advice. I've tried spraying starter fluid into carb directly but didn't crank engine while doing that. Also, into the head spark plug holes to no avail. I will try your method and keep spraying while cranking. Thanks again.

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Okay folks. I've tried all the suggestions and then some. This old ford just ain't going to fire up. I'm going to set it aside for a while, as I can't keep wasting so much time on it right now. I have a '49 Mercury woodie I need to re-do the wood tailgate and my '51 ford f1 I gotta get into a paint shop somewhere. Now, the way this tractor died on me, rapid power loss leaves me to think perhaps I need to tear the engine apart and look at everything. Maybe the distributor drive gear has spun and the timing is off, but this old engine is tired and needs new Pistons, rings, cam, bearings, etc. gonna have to wait a while before I can get to it. Thanks again for the help.