Metal on metal noise

[8Frank8]

Yamaha P60 outboard 2 stroke. After only about 2 mins at full throttle I heard metal on metal "clank" sound almost like I hit something with the prop but I felt nothing in my throttle hand. As I kept going it happened again about 20 seconds later so loud it scared me so I shut down the engine and checked the prop. Not noticing anything I idled back to the boat ramp without any issue. I took it out again 2 weeks later and within 200 yards of the ramp it made that sound again but not as loud. I have no idea where in the engine this could be coming from or what is causing it. Appreciate any help or guidance.

 

[tommarvin]

Is the lower unit full of gear lube.
Drop the Lower unit and check for any problems, any gear oil leaking out, splines look ok.on driveshaft..
Remove the head, any scoring on the cylinder walls or, burned up pistons..

 

[dpoff]

If you have the anode above the prop make sure it hasn`t loosened and hitting the prop. I`ve seen and heard is as a boat was going by on the river were we were sitting. They stopped the boat and got out to look at the outdrive. We went over to help and found the anode loose. Went up to the house, got some tools and fixed them up. Just throwing that out there.

 

[tommarvin]

I forgot to say, do a compression test, or a leakdown test first to see if there's a compression problem, before you remove the head to check for scoring/problems.