I just bought an old excalibur Hawk. The port engine needed a distributot I was told when I bought it. I took it out a few nights ago and the port engine ran terrible. It would just die when you put it in gear. I put a new distributor in today, and it idles smooth, timing right on, no popping, but it is sluggish and it sounds weak compared to the starboard motor. Best I got was 35mph out of it tonight. When I crack the throttles, the starboard sounds crisp and strong, and the port has a quieter exhaust and is just sluggish. It doesnt pop, or backfire, just sounds weak. Its one thing to not have the power the other engine does, but the exhaust itself doesnt sound the same as the healty motor. they both have good oil pressure and temps. Changed the fuel filters and no help. What could it be?

Run a compression test. All cylinders should be with 20lbs or 10% of each other. Sounds like you have some dead cylinders. If the engines are stock you should see about 125lbs per cylinder.