Rough idle

[MOOMBA_97]

I have a 1997 Boomerang with a rough idle. Motor is the 5.8 Ford. I have changed spark plugs, wires, distributor cap, rotor button, rebuilt the carburator, and have adjusted it numerous times. The boat feels as if it has a choppy cam in it at idle. The boat pulls strong with no lag in acceleration. I feel the carb should be the problem but as I said it has been rebuilt and adjusted several times to no avail. Anyone have any tips or ideas?

[Buttafewcoe]

Is the idle set low? Should be around 700-800 rpm's. Has the motor been rebuilt and cam'd? Mechanical or electric fuel pump? Altitude?
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Prolly should provide a lil more info.
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B

[MOOMBA_97]

Has a mechanical fuel pump. Motor has never been rebuilt and has between 300/400 hours of use. Not sure of the altitude but is located in extreme South GA. Idle is set correctly. Have also changed the fuel filter. Looks like I may just have to deal with a loping motor at idle.

[qb12]

instead of just living with it, why don't you take it to a dealer to be looked at.

i would much rather pay a little $$ than to be stranded in the middle of the lake. :P

[MOOMBA_97]

This is not a problem that I think will leave me stranded. The boat has performed flawless since owning it ( 3years). My closest dealer is approx. 4 hours away so without major problems at hand that is not a good option. I have riden in several other inboards (carbed) that seemed to be smooth. Maybe I'm just trying to turn it into an EFI.

[Buttafewcoe]

Extreme South Ga......umm, lots of humidity perhaps. Are you gettting any soot on the transom from her running rich, maybe? Engine reaching proper operating temp? Secondaries on the 4 bbl all the way shut @ idle?
Float @ proper setting?
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Say it runs good while cruising, eh?
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Where's Engine Nut when you need him?
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B

[MOOMBA_97]

There is a little bit of black soot around the exhaust pipes so it could be running a little rich. I have tried the lean/rich adjustments at many different settings and actually have it set at the best setting. I am assuming the float is set correctly as it was done by a mechanic.

And you are dead on Buttafewcoe, humidity is a killer here!

[Buttafewcoe]

Okie, runs good w/ rpm's up, lopes @ idle.
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It's prolly got a PCV valve, check it. Then look for a vacume leak (carb mount bolts, etc,)
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Hope this helps
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B

[plumcrazy]

Okie, runs good w/ rpm's up, lopes @ idle.
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It's prolly got a PCV valve, check it. Then look for a vacume leak (carb mount bolts, etc,)
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Hope this helps
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B

+1 on the vacum leak. I could suggest what to spray around the carb to see if it affects the idle, but I'm sure it's not the safest method (wink wink)

Dave

[MOOMBA_97]

I'm going to do some checking this weekend. I remember the bolts on the front and rear bowls being a little loose before but that didn't make much of a difference. I've got a friend who had a '80 Nautique that claims these engines idle this way. Says that it is because they were performance oriented. Given that he could never keep that thing running even half way right (I have towed it in on more than one occassion), I don't value his opinion much. I ahve heard that there are a few other manufactures that make a better marine carb than the Holley. Is this the case? Thanks for all the tips and any more advice is welcome.