61 Comet re-start trouble after running a while

[Pete W]

Hi,

When I start my 1961 Comet (144, 3 speed manual, auto choke) it starts great the first time. As a matter of fact it has never run better. The only trouble is when I run an errand and it sits for a few minutes. When I get back in and try to crank it tries and tries but doesn't start. Only when I mash the accelerator all the way to the floor will it crank, and that's after a couple of tries. Some times it's not too bad, other times it takes forever. The timing and carb mixture/idle screws all seem to be in order. Any idea's?

Thanks,

Pete

 

[page62]

Let me get this straight. The starter won't turn, unless you mash the accelerator pedal. Offhand, I'd suggest starter heat soak...except for the part about the gas pedal...

 

[TucsonHooligan]

Sounds like its flooding. Whne you push the pedal to the floor, you help clear it. Mine does something similar. You may want to check your float level or renew the needle altogether. Try that and see if it helps. If its the same carb as on mine, you don't even have to pull the whole thing off the manifold, just undo the screws that hold the top on, you can access the bowl and flaot mechanism from there fairly easily. The parts to rebuild that section should be cheap as hell and available anywhere.

Jim

 

[BIGREDRASA]

Toss out the plastic float and install a brass float.

 

[pedal2themetal45]

once you've started it and ran it when you shut it off pull the air filter and see if you can see a cloud of smoke down the carb.. if so that would be fuel flooding the motor... might be the power valve, or the float or needle and seat sticking..'
tim

 

[Pete W]

I replaced the needle and adjusted the float and it still has trouble starting again after sitting for a few minutes. Are you guys sure the problem is in the carb?

Thanks,

Pete

 

[woodbutcher]

What is happening is a thing called "Percolation".It is caused by the heat from the exhaust manifold boiling the gas out of the carb,and into the intake manifold.
When you hold the gas pedal all the way to the floor,it shuts off the idle circut allowing the engine to pump the overly rich gas charge out of the cylinders and intake manifold and finally fire.
Try and find or make a heat shield for your carb and most of your hot start problems should disappear.
Leo

 

[Pete W]

Thanks Leo,

How would I make a heat shield and where would I install it?

Pete

 

[woodbutcher]

You can use fairly thick aluminum sheet.Put it where it will deflect most of the heat from the Carb area.
Leo

 

[BIGREDRASA]

I replaced the needle and adjusted the float and it still has trouble starting again after sitting for a few minutes. Are you guys sure the problem is in the carb?

Thanks,

Pete

Toss out the plastic float anyway. The plastic can become porous and soak up fuel, making it heavier, thereby dropping the level when soaked. Even if the plastic float is still good, the brass float is good preventive medicine.

 

[Pete W]

It has a brass float. It is a Holley 1908 one barrel. What I'm trying to figure out is how to make the heat shield. Do I just try to protect the bowl or the whole carb?

 

[BIGREDRASA]

OK, that's one potential problem crossed off.

Do you still have the water heated spacer between the carb and the intake? If so, you might try by passing the water hoses, so it doesn't get heated as much. If that doesn't work, use the spacer or a gasket for a pattern, then mount the heat shield between the spacer and carb. Make sure you make a hole for the vacuum passage in the spacer.