need recommendations

[vimax]

Hello,

I would appreciate any recommendations from people in here. We have a 1994 7.4 l Mercruiser that we will be taking out of the boat (28 foot Crownline) and rebuilding it. We ran the motor 3 weeks ago (with water supply) and it ran fine, but few days ago when we tried to start it? we found water in 2 cylinders. Motor has less then 100 hr. on it, but the boat sat on the previous owners driveway for about 4 years without being started (boat is in Florida, so there is no chance of freeze damage). We used the boat back in February and it run fine (other that some water pump and bilge pump problems). Anyway, since we are taking the motor out, I was wandering if you guys have any recommendations as to what else we should be looking at or replacing. Also, is it worth to invest in fresh water cooling system (closed circuit cooling system?) for this boat and motor. Any recommendations will be great.
Vimax

 

[Haut Medoc]

Re: need recommendations

Welcome to iboats.....
I'd be looking at replacing the exhaust manifolds/risers especially if it is used in salt water.....
I'd wager that is your problem with water in the cylinders & you might get some more life out of the engine if they are replaced .....
Your engine is too old for a closed system, but if you repower that would f be an option.....​

 

[vimax]

Re: need recommendations

Thank you Medoc.
I have another question, there is a number (S1350039) stamped on the side of the block. Would this be the number that I have to give to Mercury to order a engine manual from them? Also, can anyone tell me by this number if that motor (7.4L 454 marcruiser) is 330hp, or more?
Thanks, Vimax.

 

[vimax]

Re: need recommendations

More questions

Could anyone tell me if redoing cylinders at 30 over (whatever that means???) in 7.4L 454 V8 ? 330HP (1994) will increase horsepower and by how much? We have a Bravo drive and I am concerned if the drive can handle increased HP.
Also, I need to get a set of exhaust manifolds for it, however I can?t locate engine number (numbers on flame arrestor are missing, and the one by the starter is S 135039). That number does not match anything?Are the manifolds standard fit for that engine and year?
Thanks for your help.
Vimax

 

[Coors]

Re: need recommendations

Double thread, but it does freeze here in Florida

 

[HT32BSX115]

Re: need recommendations

Going 0.030 over STD size won't make any difference. Don't expect any.

GO here for manifolds/risers etc.


Cheers,

Rick

More questions

Could anyone tell me if redoing cylinders at 30 over (whatever that means???) in 7.4L 454 V8 ? 330HP (1994) will increase horsepower and by how much? We have a Bravo drive and I am concerned if the drive can handle increased HP.
Also, I need to get a set of exhaust manifolds for it, however I can?t locate engine number (numbers on flame arrestor are missing, and the one by the starter is S 135039). That number does not match anything?Are the manifolds standard fit for that engine and year?
Thanks for your help.
Vimax