Timing/carb problems

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Nov 2, 2024 | 04:36 PM

RemingtonCG

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Timing/carb problems

I am working on my 73 f100 with the 360 ( or 390 haven’t confirmed exactly what it is yet ) and I can’t for the life of me get it to idle right. The only way I’ve gotten it to run is with the curb idle screw all the way in and the timing at what I think is around 30 degrees initial. It will “run” but it’s idling at like 1100 rpm and detonating really bad. I’ve set my transfer slots and initial timing several times but no matter what I do it just won’t idle. Am I doing something wrong? I’m setting initial timing at 13 degrees and mixture screws at a turn and a half.

Nov 3, 2024 | 11:57 AM

f5fordgirl

Fleet Mechanic

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Check for vacuum leaks first, then set the timing as close as possible, then turn the idle screws out 1-1/2 turns, warm the engine up, and work from there.

Nov 4, 2024 | 01:06 PM

RemingtonCG

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Quote:

Originally Posted by f5fordgirl

Check for vacuum leaks first, then set the timing as close as possible, then turn the idle screws out 1-1/2 turns, warm the engine up, and work from there.

will give it a try tonight and let you know thanks

Nov 6, 2024 | 05:53 PM

DrCharles

More Turbo

Joined: Oct 2009

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From: West Plains, MO

I also think you have a large vacuum leak... mine behaved almost identically, and I had the wrong gasket under the carb. It had almost but not quite enough width behind the carb to follow the flange.

Nov 7, 2024 | 08:07 AM

RemingtonCG

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Quote:

Originally Posted by DrCharles

I’ll check that out this weekend, I redid the base timing and carb adjustment again and still no better. If it’s not a vac leak thinking I’m going to pull the timing cover and see if it skipped a tooth, it’s a pretty high mileage motor so thinking it’s possible.

Nov 10, 2024 | 11:06 PM

tbm3fan

Cargo Master

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From: Concord, CA

Have a vacuum gauge?

Jan 13, 2025 | 04:32 PM

RemingtonCG

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I’ve been messing with it some more and have verified no vacuum leaks timing is as good as I can get it without it running properly I have been through the carb twice now finally did a compression test and everything looked good except for number six, which had about 30 pounds so I’m still pretty stumped but now I have that to deal with too lol