Engine lags when taking off (WOT)

Blu Coburn

Recruit
Joined
Jul 22, 2012
Messages
3
Hello everyone. I have a 2000 Bayliner with a MCM 4.3 Alpha Engine w/ carburetor, and just recently it started lagging real bad when I take off from a dead stop to 3/4 throttle... Its acting like its not getting good fuel as it may run "slow" for 5 or 6 minutes but will finally pick up. You can notice when the throttle start to fully engage as it'll pick up RPM's - then lag back down - pick up RPM's - lag back down... and then just take off. I thought it may be a clogged fuel filter, but I can't seem to find it? It has given me any problems until recently... I've also noticed that its been harder to start. Any advice would be greatly appreciated.

Kind Regards.

Blu
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
51,883
Re: Engine lags when taking off (WOT)

with the air cleaner off, have someone actuate the throttle a few times while you look down the throat of the carb. you should see two streams of fuel squirting. however with what you describe you probably wont because it sounds like the accelerator pump is not working.

carb rebuild time.
 

cr2k

Captain
Joined
Mar 19, 2009
Messages
3,730
Re: Engine lags when taking off (WOT)

Carb overhaul time. Sounds like accelerator pump and/or float level.
 

Blu Coburn

Recruit
Joined
Jul 22, 2012
Messages
3
Re: Engine lags when taking off (WOT)

with the air cleaner off, have someone actuate the throttle a few times while you look down the throat of the carb. you should see two streams of fuel squirting. however with what you describe you probably wont because it sounds like the accelerator pump is not working.

carb rebuild time.

Thanks Scott. I will look at it tomorrow evening.
 
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