How many hours will a Merc 7.4 MPI last???

[longboatsailing]

I have about 650 hours on mine and it is running great. What is the expected number of hours on one of these engines? I don't know if I need to start saving for a replacement, or if I am still in the break-in period.

 

[skolbe]

So many factors- primarily maintenance and how it is run. But you should have a lot more life in that engine. It should hit from 1000 to 2000 hours on it if maintained properly.

 

[Double D]

I also have about 590 hours on my 7.4 EFI motors. They run great....NO oil consumption and both have good compression. I change the oil & filters (gas & oil) 2x a season.... once before I wrap it for the winter....and once mid summer...(along with other maintenance). I don't push them over 3500 RPM's....I only run them at full throttle....for a few seconds.... to get her up on plane. I'm expecting to get about 1500/1800 hours before I need to rebuild / repower.

My 7.4 Westerbeke generator has an unbelievable 1,980 hours on it and that runs fine also.

I guess its all about maintenance.

 

[sbw1]

It's all about the maintenance, where you boat and how you load it. Properly propped and cruised at 3500 or less it will last a long time. My 350 Merc went for about 2600 hours and was not close to worn out when I sold the boat. It used no oil and had good compression. Police boats with Crusader 454s go 5000 + hours even 6000. When they quit, they just throw them away and start over. There lots of 20 year old 454 boats running around in Lake Michigan that are not worn out. We never look at risers because the water is fresh and clean. Impellers last forever too. You do need to keep the oil clean and run them properly.

 

[longboatsailing]

per sbw1 "My 350 Merc went for about 2600 hours ".

Thanks sbw1, that is what I am wondering. How many actual hours has been experienced when you maintain it properly? I always hear people say it should last XXXX hours, but I am curious as to what boaters who use their boats are actually getting.

 

[SLW]

We saw 1,000 hours a month ago. They burn little, if any oil between oil changes. They start right up and cruise happily at 3400-3500 and 23-24 knots. I don't want to tempt fate by saying any more.

 

[MrsRobinson]

We have Jasper Long Blocks, installed about 150 hours ago. We were told to expect 1500 - 2000 hours.

However, to me it's really not about the hours. For example, we hull speed cruise for almost 30 minutes to get to a point where we can put her up on plane just to leave the marina. We then have 3 no wake zones to go thru. So, just to get to our favorite watering hole on the weekend we put 2-3 hours on her, where less then 1 of those hours is at cruising speed. I will sometimes let her idlewarm up at the dock for 10 - 15 minutes. Add this up over a summer and you are at 5+ hours easy.