1991 Johnson 150hp cutting out at 2800-3000 RPM

DFA

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Aug 5, 2009
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4
New guy here, but I really need some help. My boat has been sitting for about 6 - 8 months(same gas 1/4 tank) and ran great last time I took it out. Anyway, I took it out and the boat started up a little slow, but ran great once it started...It ran normal through the no wake zone, but when I tried to take off it started cutting out at 2800 - 3000 RPM's. It's been at least 5 years since the carbs have been worked. A friend and I put a compression gauge on it and all 3 cylinders on one side had 100lbs. compression, the other side 1 cylinder had 100 lbs. one cylinder had 95lbs. and another cylinder had 90lbs. I don't have any idea where to go from here except a card job and new gas, so any help would really be appreciated
 

junior1113

Senior Chief Petty Officer
Joined
Jan 29, 2009
Messages
763
Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

compression is good. good starting point get rid of gas. rebuild carbs.
 

DFA

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Aug 5, 2009
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Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

Thanks Junior...Any more suggestions??? A friend of mine told me I would maybe need a power head, but I dont think I do.
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

$4000 for a new powerhead vs $120 for 6 carb kits..

hmm tough decision.:D
 

DFA

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Aug 5, 2009
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Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

Yeah Jones not a tough one at all
 

DFA

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Aug 5, 2009
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Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

Hey guys, just wanted to give an update. I hae good news...I clean the exterior of the engine really good, adjusted the throttle linkage, and hook up the water hose attachment and the boat ran like new. I don't know what happened, but I am going to run a bottle of seafoam through it with some new gas and see what happens. Thanks for the help guys
 

junior1113

Senior Chief Petty Officer
Joined
Jan 29, 2009
Messages
763
Re: 1991 Johnson 150hp cutting out at 2800-3000 RPM

advise-running motor on the hose is way different than under load in the water.
 
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