As my boat has now exceeded 500 hours on the stock 525sc's I'm at a crossroad on where to go, LOL.
I know it's most likely time to refresh.
Last year I had a wide variety of responses on the should I refresh soon as the boat I'm purchasing has almost 500hrs.
My reply's were everything from it should have been done at 300-350 all the way to Merc Racing tested these for 1000hrs at 5000rpm "Don't worry about it". People, That's a big spread!!!
My engine survey came back with excellent results from the Team Mercury service center except that they recommended changing the blower oil.
Reading some of the member's posts here where they discuss how long they waited or are still waiting to be finished made me think of just spending more and buying new motors and then either selling mine as is or refreshening them and giving the guy with the old 38 Scorpion a call to try to purchase it at a better price, and then dropping mine in a a boat for my son and his family to enjoy or selling them after the service.

So in my price range I've found a new 525sc and a 502cid 525sc clone and a pair of 468cid BM420sc'd motors with very low hours.
I'm curious as to how y'all, the most knowledgeable group I've ever stumbled across, feel about running a 502cid and the 454cid -vs- the matched pair. If I go with the SC and it's clone I can use my intercoolers since they don't have any.
My feeling is that the power output should be very close and as long as I keep rpm's close it shouldn't be a big deal, and if I go with the others I just have to do without intercoolers.

Thanks in advance for any insight y'all may have.
You guys and girls are always the greatest source of quality insight I've ever had on powerboating.

See ya,
Kelly

if it were me i would buy a ''new'' pari of 502's,send out the blowers for a rebuild ,swap all your assorys over and when the blowers came back install them and put the motors back in..i think michigan motorz and eagle engines has the 502's for around 6500 ea..

I would change my blower oil, run the rest of the summer. Unless you are willing to wait. If it was me, I would rebuild what I have instead of buying something unknown. I would question the B&M 420 parts that were used then in comparison to a new one of today, say; Blower Shop, Whipple, BDS. If you have run for 500hrs trouble free, step- up what you have and make it better.
Mark

Kelley if I were you I would change the Blower oil and then once the season is over due a rebuild on the engines and send the Blowers off to be refreshed. I sent my Blowers with Tom's to Supercharger USA. I heard Tom gained 6 mph on his boat after he reinstalled the Blowers from being freshened up. I had mine "Blueprinted"; basically their Stage 4 rebuild and it took mine about 8 weeks to be completed. As you know my engines are still in the shop getting a total rebuild done on them. If everything goes right you would probably be looking at 2-3 months max to get all the work done.

You should re power and sell me one of those 525sc's on the cheap

X2- Your engines are a known quantity. Run them until a refresh is needed then make a decision. Put $ in the piggy bank in case you want to go "big".

Wannabe

x 3

x4. those engines have already earned your trust!!