Re: 6HP stops pumping water at high RPM (1967, new water pump)
The inlet screen and plug are still in place and clean. My wife is tired of me spending time on the motor and not with her, and my 6yr old son is really getting into fishing and these two things heavily influenced my decision to take the speedy route and buy a new motor. I am keeping the Johnson and if I ever get time to work on it I'll drop the lower unit and check out the water pump before removing the head. I'm a very mechanical guy, but I took it to a pro for the water pump when bolts started breaking off. Now that the problem bolts have all been replaced, it should be easy to get back into it.
That said; the replacement is a new 6HP Tohatsu 4-stroke and I took it out for the first time yesterday. Man, I really miss the 2-cylinder 2-stroke Johnson! 2 hours on the new motor, and it starts reliably, shifts nicely and idles consistently, but it shakes like hell! It's a single cylinder 4-stroke and obviously doesn't have a counter balancer. At idle it's not very bothersome, but at mid-speed my whole aluminum boat is vibrating like one of those brook stone massager toys, and the vibrations make a lot of racket. With only 2 hours on it I haven't allowed it to reach peak RPM yet, but I gave it full throttle for a few seconds and the power seems similar to the old Johnson. After 2-hours of trolling around with my son, I burned probably 1/6 gallon of gas (half of the 1/3 gallon integral tank), so it is great on fuel. It's not smooth like the Johnson, but it will allow me to go fishing with my son so all is good. Thanks a bunch for all the tips!