Accidentally ran 2 stroke mercury 15hp without oil for an hour.

[spanna888]

I accidentally did not mix my oil into the fuel for my Mercury 15hp and took it out for the morning only to find it lacking in power and when trying to drive it kept shutting off (i now know it was overheating). I immediately drove the boat back to the boat ramp after realising my mistake and when i got home i waited for it to cool right down. I then poured a bit of two stroke oil into both cylinders through the spark hole and it fired up straight away and stayed running for well over 20 minutes idling without issue running off a properly mixed 50:1 ratio. I want to know if my motor is going to be permanently damaged or may i have dodged a bullet?

 

[Chris1956]

Normally the rings fail first, when you run w/o oil. Take a compression test and see what you have. The cylinders should be 90+ PSI and within 10% of each other.

 

[racerone]

Was the fuel tank empty when you filled it ?-----You can get away with this mistake for a few minutes.----But after that much time and repeated stalling it may be too late.----Compression test is #1 thing to do , post your numbers.----And remove bypass covers to have a look at pistons / rings.---Super easy and costs no coins to do.

 

[Faztbullet]

If its a late model Merosil block it needs rebuilt

 

[chrisgt]

If the bearings don't make angry sounds under load it'll probably still work.
You almost certainly scored up the cylinders, how much? Who knows, take a look and do a compression test. My guess is that it'll make less power than before but otherwise still work.