500 Efi ?
 

went to have a look a this 38 fountain. its nice and has a pair of 500 in there. anyway i was told that it will need a top end rebuild @ around 400 hrs and a total rebuild @ around 800 hrs.? is this true? she currently has 350 hrs on the engines.... so will it be needing engine work two weekends from now? i guess an engine like this has fine tolerences? or am i being lead down the garden path?.......

On the whole, what you are told is probably pretty average. As long as the valve springs were checked replaced at 200-250 hours, you should be able to get 500 out of the whole package before going real deep. But that all depends on how hard they have been run.

Try to get it on a computer/scanner and see what the RPM spectrum has been for the engines. If they have 150 hours of idle time (some people have REALLY long no wake zones, esp. in Florida), they might be healthier set of engines than you think.

Use the rebuild costs as a way to set your offer price.

We have an AT owner that has over 900 hours on his 37AT and he past the 700 hour mark before he had to go deep into the 500s.

500 efi has no problem with spring. That was the hp 500 again efi 500 no problems .

Like anything it all depends on the maintenance. They are very good engines. A freshen up costs a lot less than a failure!

I freshened up the top half of mine at 300 hrs to be on the safe side. Everything looked good when I pulled them apart.

Change the oil every 30hrs and you should be good until 700hrs . Great motors...

thanks for the information. good to know... what do you think would be a fair number to pull off their asking price in order to have the top end rebuilt? or do you think it would be best to pay them the asking price but ask them to service the engines before i take posession. ... only thing is how would you tell if the work would be completed? someone could just give the engines a real nice cleaning and send me on my way... i guess there is no warrenty on a preowned boat?

Why not have the engines looked at from a reputable shop and have them do a leak down and comp test on them, maybe cut the oil filters apart as well to see the amount of bearing material in them, that way you atleast have an idea of condition. shouldnt cost all that much and ask to have it as part of the sale to determin rebuild cost.

Another 500EFI rebuild question. 500EFI's have been out for about 10+/- years. Would it be a problem rebuilding the blocks that have been cooled by salt water there entire life. in other words, can the block have too much corrosion to rebuild it? Or is there way too much iron to be concered? Not trying to steal this thread - just wondering about buying older rebuildable 500EFI's. Thanks

The block you have now has a bore of 4.470". It can be bored to 4.600 in an optimal situation. Since it has been run in salt water, it will have some corrosion that eats away at the backside of the cylinders. What it can be safely bored to now depends on the amount of corrosion. The only real way to tell is to have the cylinders sonic tested. However, it must come apart to do this. You should definetly be able to bore it at least .060 without any problems. I have never seen one with so much corrosion that it can't be bored at all. You should only have to bore it .030 to do a standard rebuild. If you are looking for more cubic inches, then sonic test it to be sure that you leave about .300 wall thickness. Any good machine shop can sonic test the block. The Gen VI blocks are not as prone to corrosion as the older MK IV blocks since they have siamese cylinders. The water can not make it all the way around the cylinders to corrode them. In the older blocks, there is a water passage between the cylinders, so the water can get to all sides of the cylinders.
Hope this helps, Eddie.