questions about 500 EFI's
 

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I am looking at a boat for sale with 500 EFI's that have just under 300 hours.

what maintenance should I expect in the near future ?

how many hours can these engines go before they need to be rebuilt ?


any feedback on these engines will be greatly appreciated

thanks in advance
gary



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Many will tell you at those hours the top ends should be freshened. Head gaskets upgraded to Mls vs the stock single layer which are prone to failure. Valve springs are also a hot topic, 250 hrs is the common interval on the stock springs. A broken spring will make a disaster out of your internals after the unsupported valve drops into the engine.

Other wise maintenance will be similar to any merc bbc engine.

Agree on the head gaskets, have seen way to many go bad 250-300 hours, good advice from 4bus on the springs.

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thanks for the feedback

so if I were to buy this boat Im guessing I should do "the top ends" right away

how much approx. does that cost ?

trying to figure out how much I want to offer on the boat

thanks in advance



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if u get to them before some thing go's it will run u about 2 to 3k per motor. if u have to do a full rebuild on one if some thing go's its around 8k. im at 345 hours and i broke one so now it has all been adding up. if u have one out and the other top off its better to just do as much as u can because its all open. and it adds up fast, i was just looking to do top ends for 4k and now 4 months in im at 20k.

read this one i started before getting my new boat covers what u r asking just faster lol
http://www.offshoreonly.com/forums/g...7-500efis.html

I was thinking as soon as I get the boat , before I even use it , I address this "top end"

so... I need to do valve springs and head gasket


anything else for maintenance ??? while Im at it ?

impellers, plugs,cap,belts and filters r always good to do too

i would do the lifters to that is what broke on mine and coused the full rebuild with a new cam
[IMG]http://i1149.photobucket.com/albums/...ps357058e9.jpg[/IMG]

thanks for the link

It is amazing how many boats with 500EFIs are for sale with 300 or more hours on them most don't want to deal with them and I don't blame them. IMO Mercury did a pi$$ poor job on reserching thier gasket choice. Just my observation

some would say but i still love them over the 502 efi's. we all know that in this hobby you gota pay to play.

very true statement "you gota pay to play" no argument there....

I pulled mine down with 340hrs on it...head gaskets were still good, valve springs averaged 410lbs and lifters were good. But replacing everything anyways for piece of mind.

at 345 i had one motor that the gaskets where burnt out and had hot spots on the other motor... just do them u know they wont last a nother 350 hours like the new springs u will be putting in.

Yea, maybe Iwas lucky since my motor has had a fairly easy life. Doing everything while its apart.

Some last suggestions before you spring to play with the big boys ......In order of importance ------->
1. The engines and drives are the most important parts of the boat --- So...do not trust any one's word about anything !!!
2. Take oil samples of both engines and send them off to Blackstone Labs in Fort Wayne ,In.
3. Do not trust hour meters -they Lie,Lie,Lie----have some one with the right tools hook up with the ECU and check the hours that way - only way to tell who is telling the truth...
4. You know how the commercial asks to see the paper work---- in this case if the guy claims to have rebuilt anything in the engine compartment ask to see the receipts...No one is going to throw out those if he spent thousands of dollars to have a job done.
5.350hrs should be the red line for those engines
If the guy really wants to sell the boat he will comply with your requests ---- If not walk away.


Good luck

Jim