How many hours before rebuild on a 502 MAG?
 

Thinking about buying some 502 mag EFI's, How many hours will these engines go before a rebuild is necessary?

Any insight is appreciated...

have seen 502mags with over 400 hrs without rebuilds , hours don' mean alot its how those hours were put on the engines. the hour meters run as soon as the key is turned. See if you can get a mercursier tester, it will tell you the history of how the was operated if its a efi engine. either way do compression and leakdown checks

Those Merc. testers are wonderful. They tell you so much. But there are a couple to choose from rangeing up to $1200(that I have seen). I had that one put on my motor and now I think I might want to invest that much money for it. Also any big Merc dealer/service center should have one to use.
I believe I saw them avertised on www.sterndrives.com

I have to agree with blackhawkdn, hours don't tell the whole story. My boat has 190 hours on it and about 120 of them are idling through no wake zones. Leakdown test would be the best insurance if you're looking at used engines.

I have friends with 700+ hours and still going strong,,,, I have a friend with a 454 that was over 1000 when he sold it and was still going strong........It all depends on how it was taken care of.

A friend of mine has a pair of 502 EFI Mags with 530 hours and they still run perfect.

Ron

My 420's have 703 hours as of this weekend.

Thanks for all the responses.