Motor stalls when shifting into gear

[mcgreavster]

I’ve been messing with my 1988 Evinrude 150XP for a few months now, and I’m fairly certain something I did to it is causing this issue as it never did this before and the odds of this happening on its own at this exact time seems slim.

My initial issue was the overheat alarm went off back in July (and my RPM gauge quit working) I still had water coming out tell tale and I still had good pressure on my water pressure gauge. I pulled the heads and replaced some swollen water deflectors, replaced the thermostats and poppet valves. I took the boat to the lake and ran it for 50 minutes straight and everything went perfect (besides the RPM gauge not working).

After I confirmed the motor wasn’t going to overheat again I was ready to change my rectifier out for a new one, I pulled the flywheel and stator and put the new rectifier on a few nights ago, I also put in new spark plugs. I took the boat the the lake today and my RPM gauge worked again and my battery was changing again, great I’m all done messing with this motor I thought…Until I shift into reverse and my motor dies while leaving the dock…again and again. I let it warm up extra long and finally I was able to get it into gear and go fish. It ran perfect at anything over 600-700 RPMs, but it was a pain all day long after restarting it and trying to put it into gear to move spots, it would often take 4-5 tries to finesse it into gear without stalling, after getting it in gear it was perfect.

Any ideas what I could have done?

 

[Chris1956]

A lot of those V6 motors have a shift interrupt switch. It should be located on the shift cable connection to the engine. You might see if it works, as it kills spark to 1/2 the motor when shifting. If it sticks, the engine can easily stall.

 

[racerone]

No shift switch on a 1988 motor.

 

[brodmann]

I"m pretty sure that idle is supposed to be set at 900 RPM's. I'm pretty sure 600 RPM's at idle would make a lot of motors shut off when putting into gear.