Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Admiral
Posts: 6,297
Registered: ‎07-14-2011

Re: 1980 70hp Top Speed Problem

How are you determining that there is no spark on #1?

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Mate
Posts: 1
Registered: ‎08-30-2017

Re: 1980 70hp Top Speed Problem

I had nearly the exact conditions you describe and I did nearly all the same corrections including a new power pack. Top cylinder was not firing much at all. I ran 3 cans of the B-12 carb cleaner through at about 2K RPM up to almost stalling, then letting it sit, repeat. Happy to say it simply exploded out of the 4K RPM lull to 5800 and jumps to plane now.
Admiral
Posts: 6,297
Registered: ‎07-14-2011

Re: 1980 70hp Top Speed Problem

[ Edited ]

 

 

It is best to to inject a strong solvent such as a carb cleaner or other similar product into a 2-stroke engine as they can strip away the protective oil film on the cylinder walls and bearings which could cause future problems or internal damage.

 

To clean the carbon use a product such as Evinrude Engine Tuner which is strong enough to loosen carbon on the pistons and rings yet contains a lubricant to protect the insides of the motor while it is running.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.