Mercruiser 302 888 exhaust question.

jhester

Cadet
Joined
Oct 10, 2008
Messages
20
Hey everyone, I got so much help on here last time with my mercury 700 that I wanted to see what kind of advice I could get with my new project boat. Just bought a 19' Dixie with a 302 888. I just replaced both head gaskets, manifold and intake gaskets as well. Pretty much took care of the water getting into the oil. Just have a question about the exhaust and how much water to expect coming out of the back. Have not had it in the water yet but on the muffs I get more water coming out of one side than the other until I give the engine a little juice and both give a good amount. I this normal? I cleaned both exhaust manifolds and risers before I put them back on just and I just replaced the impeller. Any advice?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 302 888 exhaust question.

... Have not had it in the water yet but on the muffs I get more water coming out of one side than the other until I give the engine a little juice and both give a good amount. Is this normal? ...

Yes.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,357
Re: Mercruiser 302 888 exhaust question.

Ayuh,... It's pretty normal,....

Did you check the condition of the exhaust Shutters,..??
 

jhester

Cadet
Joined
Oct 10, 2008
Messages
20
Re: Mercruiser 302 888 exhaust question.

Not sure what you mean about the shutters. If you are refering to the covers on the exhaust there are none, but thought about getting some. BTW anyone know what kind of top speed this package might do. Everyone at work keeps asking and I don't know what to tell them. Just curious.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,357
Re: Mercruiser 302 888 exhaust question.

Ayuh,... Look in the manual,... There are 2 backwash preventers in the y-pipe,... Shutters...
If it's ever been run without water, they get burnt up,+ fall down the pipe, sometimes causing an obstruction...
 

jhester

Cadet
Joined
Oct 10, 2008
Messages
20
Re: Mercruiser 302 888 exhaust question.

It is a 1975 model and I haven't seen a y-pipe. I will look again but according to the manual the plumbing is correct.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 302 888 exhaust question.

Ayuh,... Look in the manual,... There are 2 backwash preventers in the y-pipe,... Shutters...
If it's ever been run without water, they get burnt up,+ fall down the pipe, sometimes causing an obstruction...

Bondo-o,

Shutters on those are right at the bottom of the Y. Even if they were brand new and in place, you won't see them from the top of the Y....
 

starsnstripers

Lieutenant
Joined
Nov 30, 2007
Messages
1,330
Re: Mercruiser 302 888 exhaust question.

Covers on the exhaust? Maybe he has through hull exhaust? Just a thought when he mentions covers on the exhaust.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,357
Re: Mercruiser 302 888 exhaust question.

Bondo-o,

Shutters on those are right at the bottom of the Y. Even if they were brand new and in place, you won't see them from the top of the Y....

Ayuh,... Your Right,... That's the 3 piece y-pipe...

Good point SS,...
Wonder what he's actually got for exhaust,...
Thru-hulls don't work so good with logs,+ 180? risers...
 

jhester

Cadet
Joined
Oct 10, 2008
Messages
20
Re: Mercruiser 302 888 exhaust question.

Yes it is a transom exhaust. It does have a lot of water comming out when the engine gets a little RPM and a good bit at idle. Just wondering haven't had a whole lot of experience with I|Os just my old merc 700 outboard which I know like the back of my hand as much as I had to do to it. Wish it wasn't starting to rain so I could go and do a little more wire fixing since the previous owner mad it look like a rat next with bare wire twisted together and hanging around and run it a little more. I didn't give but $200 for the boat and trailer so I shouldn't complain that much.
 
Top