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1982 johnson 70 won't accelerate

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blue_streak

Contributing Member
starts and idles fine. advance throttle, motor picks up a little and if you advance the throttle more, engine will stall. all fuel system items replaced, carbs rebuilt. noticed timing advances to full before throttle barely moves. Help !!
 
blue_streak said:
starts and idles fine. advance throttle, motor picks up a little and if you advance the throttle more, engine will stall. all fuel system items replaced, carbs rebuilt. noticed timing advances to full before throttle barely moves. Help !!
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A little more detail info needed.just started doing this?how long have you had it?new gas tank?
Please post compression numbers.
Are you testing i the water or flush?
7/16 spark?
What happens if you chock/prime when it starts tostall?
 
boat sat for 3 yrs. just bought it. had carbs rebuilt. mechanic said compression was good. new gas tank, all new lines/primer bulb. new fuel filter. new impeller. new battery.
testing in water. idles fine. this morning I watched the linkage and the timer base advanced full before the throttle plates even moved. may try to adjust cam roller a tad.
thanks.
 
Sounds like it needs a complete sync&link.wander why your mechanic didnt do that when he did all that other stuff.
 
Stop running the engine.-----Using the choke may mean a carburetor is partially plugged.----You risk damage from running lean.-----No fuel means no oil going to 1 cylinder perhaps.
 
blue_streak said:
just curious. are the throttle linkages and timer bas supposed to move at the same time until fully open?
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No the timer base will stop advancing at around 3500 rpm,(around 1/2 way) that is when full advance happens. The throttle and carbs will keep going until they are fully open. Is the timer base moving smoothly with the throttle?
 
thanks racerone. will wait till mechanic gets back. the timer base advances to the stop as soon as the throttle lever is advanced past idle.
thanks.
 
I had a similar problem with my 1976 Johnson 70, in the end it was one of the spark plug caps that had the internal contact broken and I was running without one cylinder, but I would only realise when going with throttle fully open. Replaced with a few euros and now it runs great.
 
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