2001 40ELPT 4S issue

[john2459]

Hello all,
I have a 2001 40ELPT 4S and the problem is that it starts and idles fine, but when I run the throttle up id will die. So I restart it and instead of running it up until it dies I'll push the throttle up and down (back) several times and then it will finally catch plane out and it runs like a champ. If this was a car I'd be looking at a fuel pump issue. I have 3 new carb rebuild kits and a new fuel pump I have yet to put on. Does anyone have any other ideas? sorta scratching my head on this one.

Bit of a back story. The boat when I got it would never get past 2000 rpm so it went to the shop and found #1 cyl had some bum rings so that got fixed and when I took it out later in the season I now have the above problem.

I appreciate anyone's input and thank any and all suggestions.

 

[Chris1956]

Check compression and spark to make sure all cylinders are healthy. Is there a mixture screw on the carb? If so, can you richen it a bit and see if that helps? The 2 cycle Mercs need a bit of a rich idle mixture to accelerate, not sure about the 4 cycle Mercs.

 

[john2459]

Check compression and spark to make sure all cylinders are healthy. Is there a mixture screw on the carb? If so, can you richen it a bit and see if that helps? The 2 cycle Mercs need a bit of a rich idle mixture to accelerate, not sure about the 4 cycle Mercs.

Thanks Chris1956, I'll take a look at that within the next few days and post results. BTW is there a good starting point for the jets? (# of turns till seated and "X" turns out?)

 

[Chris1956]

On my older Mercs, 1-1/2 turns open is the starting point.

 

[boscoe99]

What is the motor serial number?

 

[john2459]

What is the motor serial number?

OT232380

 

[cyclops222]

Could be a problem with the TRANSITION stage . as Chris suggested. Or a gasket causing a vacuum leak in the carburetor.. Do Chris way first.
People lean out the idle adjustment mixture screw too lean sometimes. Save .15 cents per year ?

 

[cyclops222]

Does the motor have a true choke lever ? A Choke Squirter ? Do you use the choke system ? Back to a cold engine with a non working thermostat. Lean Idle adjustment ?

 

[john2459]

Check compression and spark to make sure all cylinders are healthy. Is there a mixture screw on the carb? If so, can you richen it a bit and see if that helps? The 2 cycle Mercs need a bit of a rich idle mixture to accelerate, not sure about the 4 cycle Mercs.

Good morning Chris1956! OK, the comp test showed #1-130, #2-130 and #3-140 and attached is the pix of the plugs (they don't look too bad) let me know what you think. BTW all 3 carbs jets were ~2 1/2 turns out.

 

[Chris1956]

Compression is good. Spark plugs look good as well. Does that motor have an accelerator pump? Does it work?