Carburettor problems?

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deacon bruce
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Joined: Sun Sep 18, 2011 8:13 pm
Location: Boston USA

Carburettor problems?

Post by deacon bruce »

Carburettor problem?

Have Amal concentric carb. Seagull, a mongrel of a few other "parts" motors ran well last time used. Wouldn't start this time (result of poor storage over winter? MY BAD). Had spark. No fuel. Removed carb. Disassembled. Reassembled in reverse order after scrupulous cleaning. Started after a bit of effort, ran high rpm, no response to throttle lever, had to choke it to stop it. Remove, disassemble, reassemble having found nothing obvious. Started it. Ran a while, responding to throttle, then stopped. Removed float bowl. Empty. Remove, disassemble, etc. Had to use socket chucked in electric drill to start. Same story. It will run, then stop. Float bowl empty. Have tried many times to clean thoroughly, always same result. Blew through banjo fitting, get sound of air passing, turn carb upside down, no hissing, hence inlet fuel valve seems to be working. When I turn carb upside down, tickler pin will not reach or move float. Reviewed exploded view(s) of carb, and float not installed upside down.

Fiber washer between plastic banjo fitting and carb body, but mesh filter lost and not replaced as I assumed since I have exterior filter in fuel line, it would not be needed, and it had run last year without filter.

Possibilities:
Float malfunction of some kind or other
Fiber washer between plastic banjo and carb body distorting when banjo tightened, impeding flow of fuel?

HELP??????
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Oyster 49
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Re: Carburettor problems?

Post by Oyster 49 »

Is the float correctly fitted to the needle? The fact that the tickler will not move the float points to a problem of float being too low? Hence fuel shutting off too early? Just a thought.
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Charles uk
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Re: Carburettor problems?

Post by Charles uk »

What is the number on the Amal carb?
Make it idiot proof and someone will make a better idiot.
deacon bruce
Posts: 61
Joined: Sun Sep 18, 2011 8:13 pm
Location: Boston USA

Re: Carburettor problems?

Post by deacon bruce »

Oyster 49
It is a nylon float. Seems to be no way to adjust float level. Groove in needle fits prong in float. No way to fit float upside down; if fitted one way tickler barely wiggles float, but in such a way that needle does not move. If fitted other way, float is too low for tickler to touch at all.

Charles uk
number on carb is 416, under that is stanped 1A
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Oyster 49
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Re: Carburettor problems?

Post by Oyster 49 »

Ah, I was thinking it was the amal twin jet. I have not had any dealings with the amal 416 I'm afraid.
Last edited by Oyster 49 on Mon Sep 19, 2011 11:44 am, edited 1 time in total.
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Charles uk
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Re: Carburettor problems?

Post by Charles uk »

Logic would suggest that your 416 is ok, perhaps the problem lies further back in the fuel system,
fuel tap & filter or the fuel pipe.

Remove the banjo from the carb open the fuel tap & the tank air bleed screw, do you get plenty of fuel through the banjo?
Make it idiot proof and someone will make a better idiot.
deacon bruce
Posts: 61
Joined: Sun Sep 18, 2011 8:13 pm
Location: Boston USA

Re: Carburettor problems?

Post by deacon bruce »

Charles: Have done already. Fuel flows freely from tank, through fuel line filter, out end of fuel line, etc, etc, etc. That's what bothers me- all logic says it should run!!! Is it possible the float is sticking? Is so, on what? What about the tickler pin not moving the float? The banjo fitting screen filter is missing, but motor has run successfully without it. Could fiber washer under banjo fitting be mucked up enough to impede fuel from banjo fitting into body of carb? Is there a garden elf, green man, troll, elf, puck or other such creature playing tricks? Shold I exorcise the bloody thing? Is the Seagull truly the national bird of Israel? Do pigs ever fly? Do Cheshire cats really smile? It has become challenge enough that I won't give up. Yet.
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Charles uk
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Re: Carburettor problems?

Post by Charles uk »

Remove float bowl to see how fast fuel comes past the needle valve, then raise float to see if it stops the flow.
Make it idiot proof and someone will make a better idiot.
deacon bruce
Posts: 61
Joined: Sun Sep 18, 2011 8:13 pm
Location: Boston USA

Re: Carburettor problems?

Post by deacon bruce »

Reassambled and installed, now runs perfectly. Why? Who cares?

Tickler pin still does not work. Why? Who cares? Motor still runs.

Gremlins, poltergiests?
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