Thanks again for all the help. On the gimble rings...I'd imagine I'll be looking for corrosion, cracking, excess play? Is there any easy tell tales to a bad one? I don't have much experience there.

I wish I had quick access to a scanner. Probably just gonna have to cross my fingers that the gauges won't lie.

On the drives they should let you pull the prop and take the plug out to see what metal is on the drain. You can use your finger to keep the fluid leak to a min.

On the "hope the gauges don't lie". In that time it was pretty common for dealers to disconnect the hour meters for test rides etc. I never found one to match the scan. Beg,,, bower, steal or pay for a mechanic to go with you. it will help anyway when doing leak down, compression tests etc. Also if you can pull a top hose off and see how the water passages look. Lots of "fresh" water only boats that are BS.

Salt or freshwater use would be a question I would be concerned with. If they were in salt and not properly flushed and left for years, the motors are probably done. If freshwater I would still plan to at least put new valve springs in the heads at a minimum.

Recommend taking a mechanic with you to inspect gimbal rings. I understand there is a gap on the bottom supposed to be at spec, the pin itself can be rusted. Youtube videos are your friend.

I will also tell you something wish I learned before I bought my first twin engine boat. If it's in below average condition it will take a 50%+ of purchase price to make it in good condition. If it's in poor condition it will take anywhere from 50-100%+ of purchase price to get it in good condition. I bought a twin engine go-fast in below average mechanical condition and it took me 100% of purchase price to get it in good mechanical condition and still needed a lot of work. And with that I realized there was no free lunch, you may consider just buying something in good condition as you will come out ahead in long-run. So you should be comparing this Donzi that's been sitting to something that cost maybe 50%-100% more and ask yourself which one you'd rather have because you could end up paying the same money.

You're facing a situation where there's a strong possibility you may not be able to do any of the check needed to understand the engines condition due to being improperly prepared for long term storage or since it's a so called fire sale it may be a AS IS situation.

The ultra low hours is cool but presents its own risks. Valve stuck to a seat, rings rusted etc. otherwise the 500efi is the most reliable of the blue motors with the mildest camshaft.