82 Black Max Mercury

[PeteyWheat77]

I have a 1982 150 Black Max Mercury that is really giving me problems. It sounds good out of the water, but once in the water it barely goes over 5 mph. I cannot figure out what the problem is. Does anybody have an Idea?

[chpthril]

Outboard????

Check for the prob slipping on the hub!

[PeteyWheat77]

Black Max 1982

I will check that out Thanks

[mtnsmith]

Is it bogging down or free revving? That will tell you if the prop is having issues. If it is a power thing then I'd look at replacing your fuel lines possibly. Merc released ethanol resistant fuel lines a couple years ago because the older lines were being dissolved and gumming up the carbs. One big problem with working on outboards out of the water, especially two stroke, is the way the exhause exits under water helps create back pressure they need to run right. My evinrude runs so much smoother in the water, it is hard to believe. The other obvious check is plugs and wires, then fuel filter if you have one. Ethanol has really been reaking havoc on older boats, being on the water almost every weekend I hear stories. I'll ask my friend, mneal, to chime in, he has a mercury outboard on his fishing boat, and he has worked on it lots. That's how I know about the new fuel lines.

[PeteyWheat77]

RE: Mercury Black Max

Thanks for the response. I will look at all those issue and maybe it will solve my problem. This is the first time I dealt with a Mercury outboard motor. We always had Evinrude motors..........no problems at all with them.

[NICKYPOO]

Overproped?

[kko]

i had an older outbaord do same thing to me it was a 4cyl. johnson though. thing ran like a champ on the hose but in the water was a joke. ended up being a bad coil and only running on 2 cyls. but you would of swore its was running on all for out of the water. check compression and strength of spark. clogged carbs could also be a culprit.

[3mk]

my other boat has a 140 hp out board it did the samething just take off the carbs and clean them .

[PeteyWheat77]

I just spoke with my mechanic, they informed me that it was a clogged fuel pump. Thanks for all the advice.