1994 Johnson 90hp no power

techman_5016

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Jun 21, 2010
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I have a 90hp johnson that runs great on the hill but when you put it in the water, it idles good but when you try to accelerate, it falls right on it's face and you can get 1/4 to maybe 1/2 throttle out of it but only if you hold the cold start choke button in. I have had the carbs aprt twice and all the jets are clean and free. could it still be carb issue or possibly a fuel pump? Am getting very frusterated with this engine. all the help I could get would be very appreciated. Thanks!
 

Bob_VT

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May 19, 2001
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Re: 1994 Johnson 90hp no power

How is the spark in ALL 4 cylinder's? An outboard will idle fine and sound good with only 1/2 the cylinder's firing.

It is often a common error.

Verify your spark first.
 

techman_5016

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Jun 21, 2010
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Re: 1994 Johnson 90hp no power

Have done that. It had two bad coils and they have both been replaced and it is hitting on all 4. It runs good as long as you are holding the electric prime in but you just can't get it above 1/4-1/2 throttle. it has no fuel to run it over that.
 

Bob_VT

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Re: 1994 Johnson 90hp no power

Sorry to say.... but yes it still sounds like a carb issue. When you re-installed them....are the gaskets sealed?
 

techman_5016

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Re: 1994 Johnson 90hp no power

i am going to pull them back off again and put all new kits in them and triple check all the adjustments and settings and see what happens. I will be back and post the results. I don't know to do if it doesn't work this time. Maybe pull the carbs off my 88hp commercial and put them on there and see if that cures the problem if completely rebuilding them doesn't work.
 

emdsapmgr

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Dec 9, 2005
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11,551
Re: 1994 Johnson 90hp no power

If the engine runs better when you push in on the key (choke) that means the engine is running lean. When you get it running, have someone constantly prime the fuel hose bulb. This will force extra fuel into the carbs. If the engine takes off and runs fine while constantly priming, then you have a weak fuel pump.
 
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