Re: 105 hp Chrysler 1961?
Put the engine on muffs and crank it up and do a compression test on a warm engine, plugs out, full throttle, screw in compression gauge. Numbers should be over 100 psi and within 10 psi of each other. Check water pump output. Bear in mind that engines that may seem to run well on muffs might not in the water under load. Check lower unit oil for water.