Just brought my boat to the marina to repair a valve tap and got bad news. Low compression in (0 and 50 in 2 cylinders) 4 out of 8 cylinders. Bottom line - need a complete valve job, PLUS exhaust manifolds and risers. Seems water was getting into the head because of the angle the engine sits at while the boat is in the water ( ). I also need 3" spacers to raise the exhaust elbows?

I don't get it. It's a 98 Baja Hammer w/ 7.4L MPI (bought new as a leftover) with only about 150 hrs and I always flush the damn thing every time I use it.

No wonder I could only get it to low 60's last summer. I am seriously considering going back to an OB.

Any thoughts?

How do they know its just a valve job??? Did they do a leakdown test????

With 0 compression in a cylinder, you could have a lot more problems.

You're gonna get hammered on parts from a dealer. New merc exhaust is like 5 times the price of a nearly new/used set. I would look for a low hour take out engine and just replace the entire thing. If you have the dealer do everything, you're probably looking at 3-4k. You should be able to find a 7.4 for close to 3k. I know my local dealer charges 8 hrs labor to remove and replace an engine.

As far as water getting into the engine because of how the boat sits, I'll call BS on that one. Leaking exhaust will cause this.
You definately should not 3" riser spacers.

One thing I forgot - it's under extended warranty. But I may have to spring for the manifold and risers (corrosion may not be covered). That may be about $1000. I never heard of the engine angle thing either, but have been dealing with this guy a long time, so I trust him.

I am more concerned about reliability - is this going to happen in another 5 years?

Thanks for the info.

See if they will help out on the manifold and riser then apply the credit to a good set of stainless exhaust. My wellcraft service man did it for my scarab, worth looking into, especially if under a warranty.

I have a set of manifolds off a 2000 Volvo BB 7hr use
they are just sitting in the garage it also has the remote oil filter mount too, make me a offer they are just sitting there, since your here in NY its just a drive away
Im 3 hrs west of the City

I have the same Volvo stuff sitting in my basement too.
One season of use.
30 pack of Bud Light and they are yours.
I'm 90 miles east of NYC.

Hey wwwTOPDJcom,
Did you buy your engine from Shawn down south?

I also have another set of heads off my 99 7.4MPI.
Maybe 120 hours, don't think they need a valve job???

30 pack ??.I have never seen one , just 24's here

buy a set of EMI's for 1K and throw the mercs away...I'd replace the riser gaskets every fall to make sure it wont happen again they cost $20 and save your butt.