Original 56 312 with vapor lock symptoms

[mc56bird]

My original unrestored 312 has always started right up, even in this heat, whether sitting 5 minutes or two hours. Suddenly and consistently now, it just cranks with no fire. This started a few days ago, and has happened 4 times in a row. Starting symptoms when cold are uneffected. I got it to fire up each time by pulling the manual choke out full, obviously quickly pushing it back in. No fuel smoke or other flooding symptoms. Once started, it ran great as it always has, including giving it some juice to see if it was starving for fuel, which did not happen. Sort of a vapor lock issue similar to my old Ford flathead. Everything appears fine visually. Any suggestions on where to begin my diagnosis? THANKS!!!

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[CSPIDY]

Maybe your fuel pump is beginning to go bad, do you have a clear fuel filter to get a visual of the fuel?

 

[captrick]

You might want to check the float levels in the carburetor. If they are to high it could cause that problem. Good Luck.

 

[mc56bird]

Maybe your fuel pump is beginning to go bad, do you have a clear fuel filter to get a visual of the fuel?

Yes, visually it all appears clear and normal. I will check my pump. Thanks!

 

[mc56bird]

You might want to check the float levels in the carburetor. If they are to high it could cause that problem. Good Luck.

Would / could that suddenly change on its own, as it started perfectly for years then suddenly something changed. Thanks!

 

[CSPIDY]

My 57 just gave up the ghost with no other symptoms prior. But there was no fuel visible in my filter at the time.

 

[Birdman57]

My original unrestored 312 has always started right up, even in this heat, whether sitting 5 minutes or two hours. Suddenly and consistently now, it just cranks with no fire. This started a few days ago, and has happened 4 times in a row. Starting symptoms when cold are uneffected. I got it to fire up each time by pulling the manual choke out full, obviously quickly pushing it back in. No fuel smoke or other flooding symptoms. Once started, it ran great as it always has, including giving it some juice to see if it was starving for fuel, which did not happen. Sort of a vapor lock issue similar to my old Ford flathead. Everything appears fine visually. Any suggestions on where to begin my diagnosis? THANKS!!!

Check your fuel lines by your exhaust if to close you will go to vapor lock had a problem with my 57 312