1992 johnson 150 idling problem

[cruss]

my 150 will idle around 1000 to 1100 rpms and then jump up to 1300 or even 1500 rpm. The thermostats and sensor have been replaced and the carbs have been cleaned. This has been going on for about a year. I noticed its worse in the winter than the summer. In the summer it only does this some of the time and operates normally otherwise. The other day it jumped up every time I would put th e throttle in nuetral. Thanks, Chris

 

[KennyKenCan]

Re: 1992 johnson 150 idling problem

You most likly have to rebuild the carbs instead of cleaning them. The needle seats are most likely worn out causing the engine not to idle. Also, the idle speed you indicated is too high, that engine should idle between 650 & 750 RPM. An idle at 1000 RPM will eventually cause damage to the lower unit. Rebuild kits for those carbs are cheap, and its not that difficult to do if you have a repair manual.

 

[cruss]

Re: 1992 johnson 150 idling problem

kenny- it should start out around a 1000rpm each time you start it and drop down to 750 or 800 after a few seconds but instead it jumps up to 1400 or even higher. thanks

 

[KennyKenCan]

Re: 1992 johnson 150 idling problem

It sounds to me that the float needle seats are most definitly worn out. Rebuilding those carbs will definitly correct that problem and make the boat more fuel efficient. Good Luck

 

[KennyKenCan]

Re: 1992 johnson 150 idling problem

One other thing that you must do is make sure that the throttle plates are closing completly. They must be readjusted after you you rebuild the carbs.