Thanks Corm and Capt for the last post regarding the fuel vent being closed. I finally got home and tried it with the vent open last weekend. Well it started up, but wouldn't go past idle and quit. Then wouldn't restart. Took me a while to figure it out. When i rebuilt the engine, The 2 center head bolts broke off cause they were corroded to the head. I drilled one of them deep enough to use an extractor, but the extractor broke off inside the bolt. Since it was such hard metal, drill bits were going dull when i tried drilling it out completely. I cooled them in water not to let them overheat. They would still go dull. So i got tired of waisting money on drill bits. I used a hacksaw and cut down the head gasket on the head's side(so i'd damage the head and not the block). Well, anyway i got the bolts out, which i head to knock out of the head with a punch and a 15lb hammer. The head was damaged pretty bad from the hacksaw. I couldn't get a new head (sincei was only home for the weekend), so i just milled this one down so that i could use the engine temporarily. I milled off about 1/16". I know that's a lot, but oh well. The pistons were hitting the sparkplugs just enough to close the gap down to just about completely zero. They would short out and the enine would cut out (of course). So since i couldn't get a 2nd head gasket to space the head back no normal, i just put and extra set of washers on the spark plugs so they wouldn't go in as far. Well the engine started up and ran pefect. I took it to the lake, and finally i got the performance i was looking for. I didn't even think it could do that. Ran 35mph. The WOT was 6000rpm though, so i brought it down to 5000. Well, I idled it down, then gave it wide open again, and it had no power. It had a miss when it would be more than 50% power, but ran good at 50% or less. And i guess it done that once it heated up. It definatly isn't fuel related. It has a high speed needle valve, and i played with it while it was runing. It wasn't missing because it was lean, and it wasn't cause it was rich either. I'm sure it's not a fuel problem. Then for the rest of the time it wouldn't go back to full power. I went home and was trying to figure out what was going on now. I ran in in a barrel and noticed water coming between the lower unit and the powerhead once it warmed up. I forgot to tighten the powerhead down to the lower unit. That's my question. With it not tigtened down could it be getting water into the lower cylinder through the exhause port and would that cause it to missfire past 50% power since the water pressure would increase to the point where it would squirt in there. I tightened it and took it to the lake, gave it power, and it immediatly got on a plane, but now i got another problem. It popped out of gear, and wouldn't stay in gear past trolling power. I know i probably rounded the ears on the clutch dog and the forward gear. Later i found out that the shaft where the bellcrank for the shift rod goes under the powerhead broke down the middle. I found a used one for $25. But i didn't get to go long enough to see if the engine would now run good or not. I had to leave home again. Do you think not having the powerhead tigtened down would cause a miss and do you think that a milled head is ok with double spark plug gaskets. There is good clearance now. I forgot to check the compression, but engine had a lot of power, and idled really good. Would using double headgaskets work ok? And Does your forward gear ears get rounded off as easily as the clutch dog ears? I could just reverse the clutch dog couldn't i? I would never go in reverse past trolling.<br /><br />Well, sorry this is so long. I'm just excited that it actually has power(for an old 40). I want to fix it to where it runs reliable and sell it and get a larger boat which would probably have an I/O. But i definatly want to fix this one up. I'd hate for someone to buy it and then it would throw a rod through the side.<br /><br />Sorry this is so long again. I'm a corporate pilot and I have my A&P(airframe and powerplant mechanic certification). Me and some friends overhaul Lycoming engines from time to time, but outboard 2 strokes have some challenges
<br /><br />Thanks a lot,<br />Max