86 merc 7.5 exhaust coming out of the pee hole

[p4pumpman]

i just got a hold of a 7.5 hp merc and rebuilt the carb on it and it runs great but the pee hole has exhaust coming out of it along with the water . ive put a new impeller on it a ive check the plugs (no water found) . dont get me wrong it has water coming out ,its just hot water with exhaust smoke .


is this normal for this engine , im use to my 08 merc 50hp spitting out cool crisp water with no smoke .


does any one know what this is please help . i would be very greatfull

 

[huntin dawg]

Re: 86 merc 7.5 exhaust coming out of the pee hole

Are you running it in a barrel of water?
If so, it's sucking exhaust into the water intake. That's why you are getting the smoke out the pee hole.

HD

 

[p4pumpman]

Re: 86 merc 7.5 exhaust coming out of the pee hole

im running it in a 55 gal drum filled 3/4 of the way full .

ill try to run it on the hose tomorrow and see how it does .

i can see how that would make sense if the exhaust is coming out the bottom of the foot and creating a gas pocket and the pump is picking it up .


ill try the hose and see if it fixes it


thanks and ill keep you posted


god bless

 

[p4pumpman]

Re: 86 merc 7.5 exhaust coming out of the pee hole

well i tried taking it to the lake and backed in to the water and it still does the same thing . it just blows out hot water and tons of exhaust smoke through the pee hole , enough to choke you out . i can even take the hose off the pee hole and it just pukes/ surges out water along with exhaust . the water is skalding hot as soon as it comes out even at first start .


does any one know if this is some kind of exhaust leak or gasket problem

any replys would be great

thanks

 

[huntin dawg]

Re: 86 merc 7.5 exhaust coming out of the pee hole

Sounds like the exhaust plate gaskets might be shot.

HD

 

[p4pumpman]

Re: 86 merc 7.5 exhaust coming out of the pee hole

im going to take it off and check it out . this has got me baffled



thanks hunting dawg for the reply

 

[p4pumpman]

Re: 86 merc 7.5 exhaust coming out of the pee hole

well well well i think i figured it out . i pulled the exhaust manifold and found the gaskets to be in good shape . but i did find that the water jacket leading into the top of the cylinder had black soot around it which means one thing ,the head gasket must be blown which in turn is causing the exhaust to enter the cooling system .


does this make sense ?

 

[Chinewalker]

Re: 86 merc 7.5 exhaust coming out of the pee hole

Your motor doesn't have a head gasket... Not sure how to picture what your describing. Got any pics?

 

[PaulO]

Re: 86 merc 7.5 exhaust coming out of the pee hole

So when you re-installed the lower unit did you place the water pump line to the block back in the block first?

Is it possible the pump water tube is not inserted fully into the block and the gas pressure is forcing its way into the block as well?

 

[p4pumpman]

Re: 86 merc 7.5 exhaust coming out of the pee hole

im sorry about that . i meant my cooling block on top of the piston . i can see a little soot in the top hole .

when i installed my pump i put the copper tube in the block first and then put the foot on . is that correct ?

im going to check my exhaust plate for holes .

im about to pull my hair out . ive got to exhaust gaskets on order now

 

[Bubbles Up]

Re: 86 merc 7.5 exhaust coming out of the pee hole

P4pumpman-
Can you please take photos of the exhaust plate,inside of the plate and the block side .I have to do my exhaust reliefs,Just curious to what it looks like on the inside. This way if I have to bring a few tools home from my work tool box.

PM or post here please.

 

[PaulO]

Re: 86 merc 7.5 exhaust coming out of the pee hole

p4pumpman

That sounds right with the copper pipe. Lets see what the exhaust plate reveals.