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Setting WOT

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DE:1

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02 Merc 40hp 2 cyl. Engine has been synced and carb rebuilt. Engine will bog down after 3/4 throttle.Noticed that at wot (when the trigger stops) the carb butterflys are not open 180 deg to opening. Is this correct?
 
Full opening of carburetor takes place AFTER timing is at maximum advance.-------Do not make any adjustment without reading / understanding what the factory manual says on this.
 
Thanks Racerone just checking mechanics work. My manual is not that specific. Trying to find out why engine bogs down after 4000 rpm when butterfly's open all the way Could this be a fuel pump problem?
 
Eng new to me had eng synced and timed. Was told prop10x3/8-12p was correct for my boat(16ft mod-v. Eng runs fine until aprox 4000rpms 3/4 throttle. Then give more throttle and it bogs and loses Rpms until I back off throttle then runs fine again. Would like to get another 1000 Rpms out of it.
 
Find a shop that has a dynamometer.--------This will test whether your motor is producing the power that the sticker on the motor says it is !-----If there is nothing wrong with the motor than it is the prop or the boat may have something wrong with it.-------May be waterlogged foam for all I know.-------------Proper testing will get you closer to an answer.
 
I don't think it's the boat. Had 89 evinrude 40 hp 2cyl that got the boat to 33 mph at wot. Will try different prop. I know the gear cases are different ratio but the rude really got it up and going. Then dyno if all else fails. ThanksThanks
 
Why would an engine bog at 4K with throttle and butterfly to spare? Very doubtful that's a function of the prop, the engine should accelerate right up to whatever WOT is gonna be, with everything 'wide open'. I'd start there ... :(
 
Was told to maybe adjust fuel mixture richer,since it bogs down with butterfly s opening wider shouldn't more fuel alleviate the probl?
 
The idle mixture is adjustable but don't think the engine has a high speed adjustment...does it? Increasing the high speed jet may help...it might just be partially blocked w/old fuel varnish.
 
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