Mercruiser 74 MPI Exhaust Steam

"I have twin Mercruiser 7.4 MP

"I have twin Mercruiser 7.4 MPI's on my 1998 Searay 330. During the month of October, I replaced the Heads/Valves with reconditioned Mercruiser parts direct from Mercruiser. I also put on new Manifolds, Risers & Elbows in September. We also purchased new bolts & head gaskets when we replaced the heads.

Currently water temp 67 degrees, air temp 72 degrees. Starboard Exhaust water temp 175 degrees, gauge is brand new.

After installation, I noticed steam coming from exhaust. We replaced raw water pump & impellor, however stem is still coming from the exhaust hole.

I have put approx 20 hours on the engine since we replaced all of the parts. The engine starts fine with no rough idle. Checked oil and it is clear, no milky color.

Also, last night I took my family out on the boat for Christmas party and heard loud poping noise (Backfire) originating from the port engine. I think this is being caused from the distributor cap & rotor, purchased parts and will replace.

Should I be concerned about the steam?"

I stated wrong engine relating

I stated wrong engine relating to back fire. The popping is coming form the same starboard engine that is having the steam issue.

"Sorry to be a Grinch, but you

"Sorry to be a Grinch, but you might have a leaking head gasket. Suggest a compression test.

Jeff

PS: Water doesn't always get into the oil with a leaking head gasket."

"Thanks Jeff, I'll have my

"Thanks Jeff, I'll have my mechanic do a compression test tomorrow. Since it has been a couple of months since I replaced the heads and put on the new head gasket, do you think the saltwater water leakage did much damage? As I mentioned the engine ran great except for the back
fire. Could the backfire be also originating from a gasket issue?
Thanks,

Bill"

..."Could the backfire be

..."Could the backfire be also originating from a gasket issue"

Possibly. You'll be sure after the comp test.

Good luck!

Jeff