kwb

My Brother-in Law has a 1988 Formula 242 with a single 454 mag (stock). When running, the Port side exhaust puts out considerably more steam than the Starboard side. The engine oil looks clean.

Could this be a leak in the riser or exhaust manifold?

Thanks for any help.

Iggy

Could be that or the side that isn't producing as much steam is passing less water. I'd look at the thermostat housing for obstructions then check the manifolds and risers for clogs.

Scott72

The 350 Mag in my last boat did the same thing. More steam out of the port side. I think someone told me that it is just due to the direction the water flows within the motor. Colder water on one side, warmer by the time it gets to the other.

Scott

Brad Perry

There was a teague on tech article a while back that confirmed it was a thermostat housing issue.

HiPerf2000

It could be a riser/manifold problem. Is that the original Exhuast from 1988??

I've had different motors steam for different reasons:

1. Bad Riser leaking water back into the manifold

2. Bad Riser Gasket

3. Cracked head

And none of these showed water in my oil ???

I don't mean to panic you, but if it is original exhuast it should be checked for corrosion and pressure tested before more serious problems occur.

Wally

may want to check the raw water impeller while youre at it! A little preventative maintenance will be good in the long run!

BajaBoss252

Mine does the same thing. 1999 454 MAG MPI. More steam comes out the starboard side though. I have wondered about this for some time. I keep asking my mechanic buddy about it when we are on the water and he just says "it's nothing to worry about" Hmmmpff...

corey

I have a 99 454 Mag MPI and it is hotter on the starbouard side also. I heard one member suggest clamping down a bit on the port side hose to force more water through the starboard side but if this is normal I guess I should leave it alone!

djm

The starboard side smokes on my boat too. 00 454 Mag mpi. There is zero steam on the port side. Guess it's normal.

Audiofn

I am with Wally. I had the same problem and it was the water pump impeller. Actually in my case the belt was slipping a bit. At any rate I put in a new impeller and away the problem went. I notice it doe the same thing when I run on the hose. More water out one side then the other. When is the last time he did his riser gaskets? I would take them off and see if there is any scalling going on in there just to be safe. If there is then he can take them off and dunk them in acid for a evening and they will look good as new

Jon