I know you guys must know this. I'm looking at a Formula 370SS, 2005, with 525EFImotors. The motors were built 10/2004. They have 375 hours. Fresh water except for, they said, a poker run in Florida. They have had regular service. Oil changes, water pump stuff. No valve checks. Original headers. What should I worry about with these motors?

Valve springs from what ive read need checking/replacing around the 300 hour mark similar to the HP500.

That and the headers leaking are the only things to worry about from what ive read.

I would rather have those engines than a 496HO any day of the week.

Here's a thread that will help you. I just had my top ends freshened and I'm around 300 hours. A couple other things are rocker arms and head gaskets. Call Eddie Young he is very helpful if you have questions on this stuff.

http://www.offshoreonly.com/forums/g...any-hours.html

Headers, headers, headers....freshwater or not...for that year motor and those hours, you MUST pressure test the headers. also you should do a compression and leakdown test. At those hours, you should be looking at a top end refresh or just valve springs at the very minimum. Sea water pump / impellers need to be changed at least once per season.... more often if you suck up sand. The most important thing when running 525's is making sure you have good water pressure/flow to those headers and keeping them cool... heat is the enemy with them...if the headers on the boat you're looking at have any discoloration/bluing of the stainless, they may have been overheated and that is a sign of potential trouble. Apart from that, they are great, reliable motors and will be good to you if you're good to them...

oh.. did I mention headers...

My 400SS with 525's just hit 400 hours, never a problem with the motors,
but just to be safe i just had the top end done on both, turns out they where both in xlnt shape, other than the valve springs that were no longer up to spec,
also as posted before HEADERS
i'm going with the new Hardin marines and never going back to the CMI's
Also you didn't mention fuel pumps, you should have them checked also.

Get your headers now, no way i would trust headers from 2004 even to harbor cruise.

As everybody said, check the headers. I just rebuilt my top ends, the motors had 460hrs on them. They were running great, did it because they were overdue and for my piece of mind.

With all the issues with CMI's, I would yank em and install Stainless Marine in a heartbeat..

And new valve springs

So has there been bad experience with the CMI GenX headers?

Thanks for replies. What would I expect to pay, per motor for new valve springs? How about headers? I don't do any of this work myself. The though of paying big bucks and then another pile right away worries me. My other choice is a 370 with 496HO's.

My headers cracked and leaked three times causing two top end rebuilds by 280 hours. Put stainless marine headers on and they have been great. Parts are less than $3000 per motor but you or a mechanic is going to have to re-drill the block to get them to bolt up. I believe they send the template.