A buddy of mine and I are trying to get an old Glasspar boat working for the summer. It's got a 75 HP Johnson Super Sea Horse model # V4AL-17S. To my knowledge, this motor is a 1965 model year. We have it running, and out of the water it revs great. In the water, it's a different story. It never achieves enough RPMs to get going to full tilt. Seems as when we use our hands to advance the timing with the cap, it picks up and runs better. We've adjusted the linkage to give us full advance and this is the position in which it runs best, but not right. We see the dot on the flywheel indicating TDC and the start mark at the distributor. We suspect the timing belt is off a tooth or two, but we've not been able to find base timing marks on the distributor. Can anyone help us with this issue? A simple photo or explanation of the mark location would be excellent. This is a $150 purchase from craigslist and it seems to be a pretty decent boat. I should note, setting the two low speed adjustments on the carb to full rich make it a little better. Again, the timing off could be causing the lean condition? Adding fuel manually through the butterflies doesn't make it take off, so I don't suspect fuel delivery to be an issue. I am an automotive technician, so I understand the lingo, but cars are a little easier than a 1965 outboard. Thanks for reading and any advice or information you can provide.