1995 Johnson 150 shuts down after 5 minutes of full throttle

[Clint W]

My motor has always seemed to starve at the top end but the last 3 outings, I get on a plane and am cruising along for about 5 minutes and I feel a bump or two and then it just shuts off. The first two times, it took over 30 minutes before it would start again and then it seemed to run okay (not great but okay) for the rest of the day. Last outing, it started up after 10 minutes.

I do have spark on all cylinders and compression. I am suspecting the power pack may be intermittent. I have checked all of the wiring for chafing and connections are good.

Can any of you help a brother? How can I check this power pack?

 

[racerone]

Possible overheat with ---S.L.O.W.---kicking in.----Do you install a new impeller every 5 years ?----Warped carburetor bowls ?----Possible issue with shift interrupt switch ?----Remember , I can not see , hear or touch your motor.

 

[Clint W]

Possible overheat with ---S.L.O.W.---kicking in.----Do you install a new impeller every 5 years ?----Warped carburetor bowls ?----Possible issue with shift interrupt switch ?----Remember , I can not see , hear or touch your motor.

Thanks for chiming in racerone. I don't think it is overheating because it will run the rest of the day after that initial period of shutdown but I can definitely look into that. I haven't installed a new impeller but the stream is strong out of the back port. Carbs are all straight and were recently cleaned up 2 years ago. Thanks for the guidance and tips for sure. I am sure it will take a bit of troubleshooting on this one, especially since it is intermittent.

 

[Crosbyman]

carbs are never as clean once they are reinstalled and passing fuel for 30 seconds.. one never knows more so after 2 years .jmho

 

[racerone]

Run with a timing light , one cylinder at a time.----Observe the flashing light when motor acts up.