I just want to start from scratch. My buddy bought a 1990 bayliner with a 120 hp force L-drive for 2500 dollars the boat had 298 hours on it and it was is nice shape no fading or dirty spots.<br />We used the boat for about 23 hours and one day my buddy jumped a wake redlined the engine to about 6800 for like 25 seconds and to make a long story short. Every ring was busted on the exhaust side, landings on the piston were broke too. <br />We took it apart got 30 over pistons bored it chamfered the ports, cleaned the carbs got a gasket set. The only problem we had with the gaskets was they did not come with the crank seals. <br />Well we put the engine together and started it up and it ran good. Next we took it on the lake and it stood right up and topped about 50 with 4 guys on it. We ran it like this for about 3 minutes and we pulled back to the dock to pick up our fail safe guy. <br />This is when it went down hill. When we restared it was missing on two holes. I took the plugs out and found that there was some slit from the honeing and I guess from the rings and pistions braking in. So I put new plugs in and we tryed it again this time it ran but is was missing once in awhile. <br />Well we took it out and back home and I figured out that number 1 was not firing all the time. To make a nother long story short one of the trigger wires broke right where the heat shriking tubing is on the termainal and not making a good connection. <br />In the process of figuring out which hole was dead I noticed that 1 and 2 when I grounded them did not make a huge difference in rpm compared to 3 and 4. Is seemed that 1 and 2 where running lean. So took some ether and sprayed it the carb that runs 1 and 2 and there was no stumble or improvement in rpm. When I sprayed it into the carb of 3 and 4 the engine stumbled.<br />So I took the carbs off again cleaned them and checked for any dirt found nothing so then I took the reed valves off and found that they were good too. When I had the reed valves out I looked at the partion seals to see if they wher out of place and they seemed fine. So I put everything together and tried it again and the same thing. If you snap the throttle fast It will stumble and backfire through the carbs a little and then rev up. When you let go of the throttle the engine on the rev down seems to be fighting it self. I was thinking that the engine has a vacume leak and that was the problem so I took carb cleaner and sprayed on the engine case by the port covers and etc. Found nothing the only thing I can think of is the crank seals. I was too scared to spray under the flywheel because of a sprak and the bottom one I did not try is because it is hard to get and the bottom holes seem fine. So now I am at a loss. Compression on all holes is 120 to 130.<br />I tried to get my local merc guys to look at it and they run like hell and the independent guy is a real ******* . Says they are junk and I am a idiot. <br />Do you guys have any idea on how to check if have leak between the clyinders or if the crank seals are bad. I have no idea what eles could be wrong.<br />P.S we changed the sator all ready.<br /><br />Please help me 