800 + hours sealed 525 to refresh !
 

Removed both from a 35 sonic today!
still sealed. No top end job ever done before. Ran medium hard on the sticks!
they ran great but... better safe than sorry i guess!:)

this is the type of day that makes me really appreciate working on my triple than on tight twins!

who said to refresh top ends around 250-300 hours? 😂

Maintained with an open cheque book... and a service schedule adopted from a leased Honda (First oil change/ tire rotation is made after the car is turned back in after 3 yrs).

Definitely says something about the 525 Blue motors - How did they leak down?

Wow, that's very good getting those hours and no issues. Mine had 550ish hours before Eddie Young pulled them this past fall. They were the common issues on the exhaust sides of the heads and the cylinders had some egg shaping in them. Full rebuilds on them and good for another 5-600 hours.

have'nt check! But might be a good idea!

what year???

thats a good question! They were in a 2000 sonic so they were not in that boat originally!
i will check the serial number and find out! Why are you asking? Reliability different from a year to another?

I thought you had 500 efi. Year 2000 boat would indicate that. They have less cam than the 525 and seem to last a lot longer.

It is in a friend of mine sonic 35
i have in fact 500 efi that i had them rebuilt / touched for the first time at 1100 plus hours

That is good news, mine are at 678, I did do the top ends around 320-350 hours. Leak down and compression test was good so new starters, sensors, headers and back in. Screw it.

i have one of the serial number
when i punch them in mercruiserparts.com, it does not say what year

anyone know how to find?

OM953167