RaggedEdge

So as years have gone by all the immediate need to tear into these motors seems to have passed, somewhat.

Here be the question of the day...…………………….????

Those who have these 525 EFI's and have opened them up in the 300 to 350 hour range, assuming you have not run the chit out of them, What are you finding? What kind of condition are they really in?

I have a pair with 325+hrs on then, last weekend they ran like bears, run hard, run well, run like they did years ago.

What are the signs that they are in distress and need work?

I am all for spending some money to keep these running their best, but how does the regular guy know when it is time to give these prized ones some love?

Jupiter Sunsation

scroll down a few threads:
Twin 525efi rebuilds by Merlin Marine

VoodooRob

We had a 2005 353 with 525 EFIs. Engines ran perfect, no issues just over 300 hrs when opened up in winter of 2014 for preventative maint.. Rockers were fine because they were early production, avoiding the exploding rocker arm bearing issues, but the head gaskets were seeping, all 4 of them. Also the valve springs were shot, a few were broke. Heads gone thru, new Johnson lifters, pushrods. Should have had the fuel injectors tested and flowed at the same time. Sent headers to CMI for testing and repolish, very in-expensive. All worth it, when we went to sell the boat with 360 hrs on it, it sold fast because all the proper maint was done with receipts to show it and it ran flawless. Guarantee the first thing anyone will ask when you decide to sell your boat is when and what was done for too end service. Its better to get into them before a problem, the repairs can and do get expensive.

BUP

I would do heads -- surely would do ALL NEW springs and lifters and so on. quality new gaskets a must and 4 sure have the fuel injectors flow tested and cleaned. Just did a 525 in MAY. 378 hours needed all what I mentioned without a doubt. If you need help with the fuel injectors let me know.

Address any header issues and or at the very least pressure test them twice per year

boatnt

is Fel Pro head gasket good since this is a closed cooling system?

RaggedEdge

Made the final commitment today to the top end redo. So what parts are you all using in your rebuilds?

I intend to change out springs, retainers changing to 10degree locks, do complete valve job, change out roller lifters, pushrods, go to Isky stainless rockers and some real good head gaskets. So what are the parts of favor these days?

H20 Toie

Good choice, on both my 2008 Cigarette 38 and 2005 Formula 400ss i had top ends done at 400hrs and all four motors were in xlnt condition except that the vavle springs were way past there prime, so i was lucky, the formula had most of its hours at idle and hardly any hours over 4000 rpm the cig was mostly at 4000 and above, the headers had been repaced on both boats twice i hate those headers

cigrocket

On Time

Mine have 380 hrs, run moderately freshwater only, always annual service Merc 25W-40 oil and run flawlessly year after year. Not much time at WOT probably 5% or less mostly 4200-4600 rpm cruising. No engine work ever. One header has a leak, fixed at CMI. Valve cover gaskets are perfect. 2/2005 motors.

RaggedEdge

Thanks to all, keep the info coming. Threads on these 525's have become few and far between compared to the old days of the 500's. Worth the discussion to see if they are just that much more reliable. Merc always pitched them as the real deal.