Since I am boatless i always keep looking around for the right deal. I am wanting to stick with a fountain and i think i want between a 35-42 My last boat was a 10 meter with 454 mags that lasted about 700 hours before needing to be rebuilt. I have seen all of the boats that i am interested in with different power and i saw the thread about the donzi with 496 or 525 and most say the 496 are bullet proof and the 525 needs top ends redone at so many hours. I guess my question is at how many hours are major services needed to be done on 496 500 efi 525 and 575 and how many hours have you seen out of said motors without any major work. Thanks

Unfortunately, I had to have my '03 496 MAG rebuilt over the winter as it reverted water and bent a rod. Other than the bent rod, the builder said the inside of the engine looked brand new (bearings, etc.). Engine had a little over 400 hours on it. Builder said it easily would have went another 400.

all 3 of the blue motors are going to have similar maintenance intervals and the 496 will run forever. The 525 is the only one with header problems, the 496 and 525 have closed cooling. The 575 is supercharged and will need premium fuel, the other 3 will run on regular fuel.

From what I read in the other thread is 350 hours when the top end need refreshed ? is that true for the 500,525 and 575? what is a good price on top end refresh and what is involved I believe I read somewhere that the super charger needed service on the 575. At how many hours does that need done and what does it cost. The reason I bring up cost is that the wife is an accountant and sees numbers she is on board for a new boat and knows they cost money and I know that unforeseen things happen to any motor combination. I want motors like the last boat I had they started and ran every time I got on the water with little to no issues

Less hassle with 496 and 525 for sure. 575 superchargers are good for 250 hrs stock and need service sooner if you spin them higher.

Of the engines you listed starting from least amount of expense is 496, 500 EFI, then 525 and 575 are about tied as they have their own individual issues. The 525 most likely to cost the most if you had to pick. If you have the better half watching the books then stick with black engines and go boating, but the drives will still be an issue in 35'-42' boats. Our 353 Fastech with 525s the past 2 years was both drives and maintenance for top ends @ 300 hrs give or take. 525 Headers are always brought up in threads. If boat was used in fresh water, side by side set-up, the header update was performed for more cooling, and the owner changed impeller kit a minimum of once a year that is your best chance at the headers being good. Pressure test will verify. As with any hobby or sport, it's pay to play. The harder you want to play the more you have to pay.

Thanks for the info. What do the top end refresh cost i saw one thing that says 12k is that per motor or for both? I just want to have ideas on what things may run on something i purchase. i know you never know the unforseen sh!t happens. but if a boat i purchase needs 15k worth of work or more 1 year after i buy it may change my mind on what to buy. I know these boats are not cheap i have owned one. I know i will never be the king of the river or the lake. I just want to know that when we go out i want the least amount of problems similar to the last boat. Thanks again for your help. Rob

Plan for 10k.

Yup I spent 11k for both on 525's

It all depends on how deep of a "top end" you do. I did lifters, pushrods, head rebuilds except rockers, belts, all filters, etc. Some people throw springs on and keep on eye on everything. The factory head gaskets seem to be something to watch also. I paid to have everything done from a certified shop, $12K for both engines. If your close to Eddie Young he is very good with blue engines and is priced better than what I paid. Also don't forget the drives, unless you get recent receipts, they will need to be inspected to avoid major failure. Both drives rebuilt will get you for $2-$6k each (aprox many variables).
Merc Race takes the owner being involved and maintaining the equipment, if you are a buy it and use it til it breaks kind of guy, black engines are your best bet.