3.0 GS PNCA carburator ( holley 2300) idle problems.

aerobat

Master Chief Petty Officer
Joined
Jun 1, 2011
Messages
842
hey gents !

today i ran into issues with my engine, most probably carburator. for best results i will try to describe it as close as possible :

we went out for pulling a banana with my boat .

after the engine started fine and idled fine for about 20 minutes ( the people took long to position on the banana ) i slowly idled out the shore , stretched the rope and the gunned the engine. it responded nice and started to pull boat and banana on glide when suddenly the rope collapsed - but thats not what my problem is.

of course i immediately retarded the throttle from WOT back to idle.

the result was the engine in this moment stalled and was not able to restart. cranking it , pumping the throttle etc resulted in unburned fuel visible on the water out of the exhaust - the engine seemed flooded. the rope was for sure not blocked in the propeller.

we removed all plugs and cleaned them, 1+2 were very wet with fuel , 3+4 a little better but also overriched.

after the cleaning and much cranking, the engine , still in overrich condition started with a to rich soot cloud after applying full throttle but had problems with idle , lost slowly rpm,s on idle and stalled again.

it still sounds rich .

we adjusted on the idle mixture screws and resetted factory settings. ( 1 turn starbod , 1/2 turn port ) . this seetings are directly a copy from a holley manual .

the engine then ran on idle but badly, we went for a little bit more lean and it improved but not perfectly. we went for a test ride and at WOT there are no issues, the boat has power, it responds immediately on gunning the engine but when you troll on idle the engine after a minute or two starts to shake , loose idle rpm,s and finally stalls - whatever mixture setting we tried.

i had some idle issues with the carb but not that bad - i previously adjusted the mixture and replaced all fuel filters and the problem was away for months, the engine idled fine and worked fine at all speeds. today it happened suddenly.

soo my questions to the pro,s here :

-does it sound typically on the 3.0 and somebody experienced this ?
-when VP/ holley says 1 turn starbord 1/2 turn port - for confirmation - it means standing behind the engine and looking to the bow , correct ?
-why are the two idle screws not the same factory setting ( 1 turn and 1/2 )

any help and hints are very welcome, thanks !
 
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