360 does not run at idle

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bjanakos
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360 does not run at idle

Post by bjanakos »

Had the boat laid up for a couple of months on the hard to do some maintenance. I launched it and now one of the motors is having some trouble running at idle. It's fine above 1000 RPM and I don't hear any misfires.

I'm thinking spark or fuel, and probably leaning on fuel since it was laid up. I'm heading back tomorrow and tossing on a new cap/rotor, new fuel filters, water separators, and dumping a few cans of sea foam in the tank. Any other suggestions or known root causes for this condition are welcome.
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prowlersfish
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Re: 360 does not run at idle

Post by prowlersfish »

I would start with fuel likely the carb has some trash ,water or varnish in it
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Paul
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Re: 360 does not run at idle

Post by Paul »

+1
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Lance F28
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Re: 360 does not run at idle

Post by Lance F28 »

It sounds like an old fuel issue. Assuming it's carbureted it may be a gummed up idle jet, a good dose of seafoam will probably clean it out.
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oldboat1
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Re: 360 does not run at idle

Post by oldboat1 »

might be the choke sticking. Some carb spray for the jets (sometimes helps), and some WD-40 for the choke linkage.
Motors should run. People -- not so much.

1980 F26, Mercruiser 305
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AlphaJustin
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Re: 360 does not run at idle

Post by AlphaJustin »

I'm with the other guys you got sediment in the idle jets on the carb.
1972 Trojan F-25 with no TRJ number and a 4 barrel
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44Ydnar88
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Re: 360 does not run at idle

Post by 44Ydnar88 »

On an edelbrock or Carter the idle circuit is in the primary Venturi, this will cause alot of weird idle problems, zoom in on the circle
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bjanakos
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Re: 360 does not run at idle

Post by bjanakos »

Thanks for all the replies. I replaced the fuel/water separator and pre-filling it with fresh fuel. No love, so that eliminated bad gas. Then I tackled the next easiest job - the cap and rotor, and viola, back in business. Several cans of seafoam added to all the tanks for good measure.
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