OK,
What is the consensous on how many hours before they need a major or minor rebuild? I know alot depends on how well maintained they are and how they are/were driven, but I just trying to get real life experiences. I have a 1999 HP500 with 120 hours, and it is running like a champ!
Possibly looking a boat with 2000 HP500EFI's with 160 Hrs?
Thanks in adavance,
MD

I didn't know MANATEES came with twins? Whats up Mean Dean?

Shane,
Very Funny!! So you had a great time sledding I see! I do miss snowmobiling, then coming inside and warming up by the fireplace! Maybe one of these winters....
Take care,
MD

You should get 400 hrs out of the motor if you treat it right before a rebuild is needed.

I've got 300 hours on my 1999 EFI's with ZERO problems.
Still run the same as they did when new, but consume a bit more oil (Mobil 1), but no smoke or soot (unless I stupidly run 93 octane).
Did have a leak in one CMI header, and all 4 of the Silent Choices had to be rebuilt. Oh, and new water pumps (after some time sucking up the bottom of Sarasota Bay).

I am right at 170hrs on 2001 efi 500. replaced one thermastat. Fires always. runs and idles great.

Will

Thanks for the replies. Let hear some more!
MD

Dean,

I had about 240 hours on my 500 EFI's when I added the Whipples. Then put on about another 100 hours before I blew a head gasket on one engine. At that point I did a compression and leak down test and they were still within tolerance. Sold the long blocks less Blowers to 2 guys (OSO members) and I understand they are running fine with over 500 total hours.

So, I can comfortably tell you that 500 hours with proper maintenance isn't a problem. However, the CMI exhaust were in close to failure mode when I pulled the engines. If you've got two years or more on your CMI's (salt water use) it might behoove you to send them to CMI to have them checked out.

Hope this helps,

Steve

I got just over 500 hours on my motor before I saw a significant loss of compression on one cylinder. The motor had broken valve springs, piston rings, and a bent intake valve. Other than wear, everything else looked good.

Dean-did you have the valve springs replaced already? If not, you're almost due for them.

A buddy of mine has twin 502s and has close to 600 hrs on them. He did regular maint. and has only replaced the risers. They're on a '99 Baja 38 Special. After putting on the stainless risers, he took a trip over to the Bahamas last month and they ran like champs.