Went out last week and at about 4000 rpms I started loosing rpms in the starbord engine. Got off the throttles and it died. Seemed electric, no bid deal. No noise, no smoke, no nothing. Tried to restart and it just clicked. Found a short in the startor and replaced it. Still was very slow to turn over. Pulled the plugs last night and OH S%$T. Take a look at the plugs from #2 and #3. Anybody got any ideas?

Twin 454 / 400hp
Gill Exhaust with Stainless risers
TRS
84 Scarab III

You are running really lean. #1 they melted down, #2 they are super clean. Your real issues now may be with the valves and pistons.

You may not be able to tell from the pics but it looks like they have been hit, maybe by a valve that got ate or something. The other 6 look fine. The only problem is in these two cylinders. I didn't think that it could run that lean to melt a plug in only two cylinders.

Heads off I'm afraid. Looks like you may have dropped a valve or lost a piston.

I had this just happen to me. I was running at only 4400-4600 RPM so I pulled plugs. All were fine accept #7. DO you think that anything could have damaged piston/cylinder/ or head by looking at this? It looks like pluge burned off and nothing looked broken. I am going to do a compression test on that cylinder, what should I do, put in new plug and run or what?

Compression test and leak down test if possible. What plugs are they and what motor are they in?

I cant tell from the pics it they are beat up from a valve or melt down. It that specks of aluminum on the thread ends?
did you do a compression test and a leak down?

It looks like something broke off and beat those plugs up. Pieces of piston or valve have been known to travel from one cylinder to another causing damage as they travel. I'd skip the leakdown and just go ahead and pull the head. There's damage of some sort there.

that is kind of what i thought. i am going to try and get it out of the water this week and get someone to pull it and see what is going on. i will probably have an ad to try and sell a great dock anchor in the next week or so.

i am seriously thinking about just replacing both engines. i have only had the boat a couple of months so who know about the other one?

Sorry for the discouraging words. How many hours are on the motors?