Johnson runs rough at low speed

[mmasterson]

Hey guys,Ihave a 70 hp Johnson ser. # J567519 mod # J70ELCNB that has a problem at low speed. The motor misfires chugs sputters and so on. As you advance the speed the misfire stops(about half throttle)and runs strong at W O T . The motor always starts(some times difficult)but acts as though its flooded. The carbs have been rebuilt, New plugs & wires one new coil,new thremostat,new gas new power pack . The compression readings were 112 top cyl 108 middle 112 bottom. I have checked every conection and wire that I can see,can't think of where to look next( under the fly wheel?).Thanks for your help.

 

[Solittle]

Re: Johnson runs rough at low speed

When it starts to sputter give the primer bulb a squeeze. If it kicks in you have a fuel delivery problem & I would suspect you still have some crud in the carbs.

 

[mmasterson]

Re: Johnson runs rough at low speed

Thanks , I'll give it a try and let you know. Thanks again.

 

[Richok]

Re: Johnson runs rough at low speed

Last weekend my neighbor had about the same problem. We sycronized his fuel to engine and it took all that out. May not be your problem though.<br />His is a 70 Evinrude.

 

[mmasterson]

Re: Johnson runs rough at low speed

I found a missing O ring...(I think there should be an O ring when you connect the hose to the engine)And a tie wrap was loose and I think there might have been an air leak there.<br />Thanks again to Richard in OK and So little<br />and Iboats for making this forum available!