1988 Johnson 140 VRO won't pull past 2100 rpm

Laker272

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May 26, 2009
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As the title states, my motor won't pull up revs more then 2100 rpm. I recently purchased the boat and for the last 6 outings everything has been running great. The powerhad was rebuilt in July of last summer. It ran fine in the morning, but in the afternoon it lost acceleration. It will rev up fine to 2100 then it won't go any higher, and runs steady at that rev but sounds boggy. I have replaced the fuel filter, and put a new primer bulb on it, the existing one was soft when pumped up. I have bought carb rebuild kits, and wanted to know if someone has some insight of what may be happening, or more importantly, what isn't happening. Thanks in advance.
 

SparkieBoat

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Aug 17, 2009
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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

check fuel..try pumping bulb while running. check all fuel lines and connections also check vent for fuel tank. check spark with a spark gap tester..needs spark at 7/16 gap...check carbs, you can do a visual inspection while running and look for even spray pattern..do not run motor for an extended period with carb cover off.
 

SparkieBoat

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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

also test over heat buzzer and make sure motor is not over heating. and after all that check compression..and do not forget a new set of correct champion plugs
 

Laker272

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May 26, 2009
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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

Compression was tested and is good.
How does one test the overheat buzzer?
The guy who is looking at it is thinking there is a problem with the timing base. Does this make sense?
 

SparkieBoat

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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

possible timer base..but it is not the most common problem...I would do a complete ignition test and eliminate any other issues like regulator/rectifier, power pack, stator, weak coils, and do a link and sync, clean carbs, check fuel pump and lines and connections...these are the most common issues, I have never actually replaced a timer base but I have heard that they can go bad.
 

SparkieBoat

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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

to test over heat alarm ground the tan wire on your power head temp sensor, with key turned on but motor not running.
 

Laker272

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May 26, 2009
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Re: 1988 Johnson 140 VRO won't pull past 2100 rpm

A big thank you goes out to you Sparkieboat. I will let you know how I make out. Cheers
 
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