Johnson 150 bogging down

Crewchief18

Recruit
Joined
Aug 8, 2011
Messages
1
I have a 1986 Johnson 150 when it's in neutral it revs fine the whole way to wot but with the prop engaged it runs fine to little past half throttle then if you go further it starts to lay over and stall out. I did the wot timing with the plugs out method. It does make it to the advance stop and the timing is correct at that point but if you go further with the throttle is when it happens. The stator and timer base are new and the power head has only about 5 hours on it. Thanks in advance for any help.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Johnson 150 bogging down

A couple of mechanical things to check. Make sure the link arm is connected between the spark advance lever and the timer base. If the arm becomes disconnected, you won't get full spark advance when the throttle opens completely. Also, check your throttle cable adjustment. Make sure the carb butterflys are fully open when the throttle handle is in the full throttle position. You'll have to pull the airbox cover to see the movement of the carb throttle plates. Were the carbs overhauled when the powerhead was done?
 
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