My motor started bogging down on the way back from duck hunting the other morning. It did this earlier this season and i had to replace the head gasket. I took the heads to get them leveled and the block itself was level. I followed the manual to the T with the instillation of the new gasket. I have checked the compression and I am at 90 PSI on all cylinders, but I am at a loss for what it might be. I was thinking perhaps the carbs or fuel pump, but I would like the opinion of somebody with more experience.