The Ford Barn

JohninKuranda · 12-04-2023, 02:04 AM

...a problem, I think, of my own making.

I recently took off my Carburettor to give it a service, replacing gaskets etc. Was a bit of a challenge as I noted that I had no petcock between the tank and the petcock screwed into the carby. So fuel everywhere until I managed to stop the flow with a clamp. I eventually drained the tank and installed an in-line tap into the fuel line.

Replaced all the gaskets in the carby and put it all back together. Did the turn it upside and suck test - I had a vacuum. It seems that whilst fuel is getting through to the bowl okay, something is preventing the engine from firing up.

Coils are sparking away as they should. It seems as the plugs are firing but there is nothing to ignite. I have checked all the gaskets and tightened every thing I can. Removed the plugs and there is no smell of fuel on the plug.

At the moment I am surmising that no fuel is getting into the cylinder. Or not enough fuel is getting into the cylinder. I have twiddled with the choke adjustment. Apart from having an air leak somewhere in the carby, and the possibility that the on-line tap, though fully on, may be not allowing enough fuel to get through to the carburettor, have I missed the bleeding obvious?

Any thoughts appreciated!

John

redmodelt · 12-04-2023, 09:53 AM

Besides air leaks, did you remember the gasket between the carb and manifold, could be that you are not priming the engine enough while starting or need to open the needle valve a bit more.
If fuel is flowing past the shut off valve, it should be filling the bowl. If the bowl is filling, that should be good enough for starting. Have you done a leak down test to check flow out the carb drain? When doing the leak down, you need to let it drain for a while so you are not just seeing what might be in the bowl come out and are seeing actual flow.
Another option would be to pull the plugs and prime the engine to start. Then do your adjustments and check for vacuum leaks.

mechanicalarts · 12-05-2023, 02:22 PM

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Have you removed the drain plug on the carburetor bowl and verified that you have fuel flowing to the carburetor?

12-04-2023, 02:04 AM	#1
JohninKuranda Senior Member Join Date: Jan 2014 Location: Kuranda, Queensland Australia Posts: 186	Engine won't start ...a problem, I think, of my own making. I recently took off my Carburettor to give it a service, replacing gaskets etc. Was a bit of a challenge as I noted that I had no petcock between the tank and the petcock screwed into the carby. So fuel everywhere until I managed to stop the flow with a clamp. I eventually drained the tank and installed an in-line tap into the fuel line. Replaced all the gaskets in the carby and put it all back together. Did the turn it upside and suck test - I had a vacuum. It seems that whilst fuel is getting through to the bowl okay, something is preventing the engine from firing up. Coils are sparking away as they should. It seems as the plugs are firing but there is nothing to ignite. I have checked all the gaskets and tightened every thing I can. Removed the plugs and there is no smell of fuel on the plug. At the moment I am surmising that no fuel is getting into the cylinder. Or not enough fuel is getting into the cylinder. I have twiddled with the choke adjustment. Apart from having an air leak somewhere in the carby, and the possibility that the on-line tap, though fully on, may be not allowing enough fuel to get through to the carburettor, have I missed the bleeding obvious? Any thoughts appreciated! John

12-04-2023, 09:53 AM	#2
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,342	Re: Engine won't start Besides air leaks, did you remember the gasket between the carb and manifold, could be that you are not priming the engine enough while starting or need to open the needle valve a bit more. If fuel is flowing past the shut off valve, it should be filling the bowl. If the bowl is filling, that should be good enough for starting. Have you done a leak down test to check flow out the carb drain? When doing the leak down, you need to let it drain for a while so you are not just seeing what might be in the bowl come out and are seeing actual flow. Another option would be to pull the plugs and prime the engine to start. Then do your adjustments and check for vacuum leaks. __________________ I know the voices aren't real but damn they have some good ideas!

12-05-2023, 02:22 PM	#3
mechanicalarts Junior Member Join Date: Dec 2023 Location: Tenants Harbor Maine Posts: 13	Re: Engine won't start Sponsored Links (Register now to hide all advertisements) Have you removed the drain plug on the carburetor bowl and verified that you have fuel flowing to the carburetor?