I bought this engine and it never ran right. I tore it down and found that the lower main bearing and seal went out and leaned out #5 and #6. I replaced all pistons and rings honed and new upper and lower main bearings and seals. Its got good even compression on all cylinders. It still misses very bad. The idle fluctuates up and down but not quite like a vacume leak. It will not rev or get on plane. The plugs are wet and carboned. I jet it for 8500' (.074). Its got good strong spark on all cylinders. While I was in there I noticed the reed valve blocks were loose on the crank. The reed petals were within spec but there was no tolerance for the block on the crank in my Seloc manual so i left them alone. I could rock them in and out (like you would a rod bearing) and there was a little play. Now thinking back I can see how there would be blow by between the cylinders. Could this be the problem?