1965 40HP. Lower unit poping out of gear or a miss?? Not sure were to start.

[supercab78]

I've been helping a friend get a (new to him we have no history) 1965 40HP 2 cylinder outboard to be water ready. On our first test run yesterday it idle well, accelerated and run full speed well MOST of the time. It acted as if though it was going in and out of gear at varies times. My question is if the lower unit dog gear slips out while under load, could it catch and hold for a short time and repeat this cycle?
I'm thinking it's the engine that's missing and making the occasional violent jerk. But I want to eliminate the lower unit as the problem.

 

[racerone]

Does the shift lever bounce on it ?------MODEL # is ?-----Does spark jump a gap of 5/16" on both leads , yes or no ??

 

[supercab78]

did not notice the shift lever bouncing. I adjusted the black plastic knob to make sure it was firmly in gear, no change. Model #, I don't know & boats 40 mile away. Did not check spark gap. Should those old systems be able to jump 5/16" ?

 

[F_R]

Everything you said points to the classic clutch dog problem. Violent jerk at intervals. People usually say it feels like they hit something in the water. If you put your hand on the shifter lever (on the motor) you should be able to feel it.

 

[supercab78]

F_R ; So it is possible for it to pop out then back in without having to slow the engine down. I had a clutch dog problem 30 years ago on a 1959 50HP Evinrude but I don't remember it going back in drive without slowing the engine. But it was 30 years ago! To fix the 50HP one I just switched the forward & reverse gears, who needs run a heavy load in reverse! Maybe I can do the same on the 1965 model also.

 

[racerone]

???----Does spark jump a gap of 5/16 " , yes or no.----A good system will jump that gap with ease !!

 

[supercab78]

racerone; did not check spark gap yet, boat is 40 miles away.