Two yr. Head scratcher, need help

[bluebear57]

I have been chasing an issue with my 89 Mercury mariner 150 for 2 years . It starts up and idles perfectly but when you give it throttle it stalls like it’s out of gas.it has been completely rebuilt including pistons and rings.I have taken it to small shops around here paid money nobody could figure it out. I replaced the fuel pump,regulator stator,trigger,power packs and rebuilt carburetors etc all things on this motor ,thinking it might be electrical,and it still does it ,in the middle of the lake last week I was on my back in the middle of the lake working on it ,in neutral, I just happen to reach up and grab the linkage for the carburetors and tried to rev it up real fast and black smoke blew out and it started running perfectly. It ran all day off and on no issues, after sits all night it does it again .I manually throttle linkage and keep it in neutral and it’ll blow out a big bunch of black smoke and it starts running perfect again , no stall but you can’t rev it up with control arm untill it clears out, then it works fine have no idea what causes that , if any of you do I greatly appreciate it

 

[Black58]

Chokes? One of these smart guys will be along I'm sure. Had plenty of street rods and motorcycles only a few outboards.

 

[bluebear57]

You would think so. mine don’t have a choke. It has an en richer but that’s what it acts like act like the jokes on it but it starts too easy when it’s cold and it’s hot but I’ll double check that thank you for your response.

 

[Dukedog]

might double check ya float height??? sounds strange?.. your problem is something i've not had and/or heard of but it is a merc, sooooooooooo!

 

[cyclops222]

Somebody has connected the Enrichment / Choke flexible hoses incorrectly.
I did that on my Evinrude . Took a while to figure out. Called my O B chief mechanic. 1 minute Cell Phone call, he guided me on the correct hookup. First time.

 

[bluebear57]

might double check ya float height??? sounds strange?.. your problem is something i've not had and/or heard of but it is a merc, sooooooooooo!

You’re so right you fix one thing on it and something else screws up but I’ll double check the float levels again thank you for your response

 

[bluebear57]

Somebody has connected the Enrichment / Choke flexible hoses incorrectly.
I did that on my Evinrude . Took a while to figure out. Called my O B chief mechanic. 1 minute Cell Phone call, he guided me on the correct hookup. First time.

That sounds entirely possible. I had a friend help me put in the final touches on my boat about a year ago and it has makes
Yeah sense lol lol I’ll double check that thank you
If I find the problem, I’ll let everybody know. Thanks again again.

 

[bluebear57]

Thanks for all your responses and all your help. Seems like when you get a rebuild kit for your fuel pump. You just get the gaskets and the diaphragm ,there are two check valves in there. They’ve always told me oh no, just put those back in just put those back in this time I said no give me two check valves , i rebuilt the pump second time since last year,guess what it runs beautifully and perfectly with those new check valves in one of those check valves was leaking and flooding out the cylinder Always something, I have been a fortune, chasing this thing, rectifiers GDI packs, carbon kits, stators, trigger, etc. etc. lots of time and money simple fix,if you buy a rebuild kit give them the whole damn rebuild kit thanks for help