I have a 1971 7.5 merc with roughly 8000 hours on it. I keep up on maintainence (impellers, carb, etc...) but have come across a new problem and am stumped. The last time I had it on the water it started on the first pull and ran great for a couple of hours, then it started getting rougher with each new start (and started sounding rough too during run, almost like a "loose" kind of sound if that makes sense). When I took it out the next week it wouldn't start. Its getting gas, carb is clean, plug is great, water pump is good, etc... Any ideas? Everyone I talk to locally says it's just plain wore out, but I want to know if it will start again. Thanks.