1970 Johnson 20 hp problem

[Nick51786]

I just bought this motor last week took it out over the weekend runs strong when I got it going. Now here's my questions it won't just start and stay running when it fires up you have to give it some gas to keep her going but then runs good. Also it won't stay running if I try to turn the throttle to the slow or shift positions it just kills it. One last question is when I try to put it in reverse it kicks and doesn't seem to want to go into gear eventually it will though . Well thanks guys for any help you can give me.

 

[Will Bark]

Re: 1970 Johnson 20 hp problem

Sounds like your carb needs a good cleaning especially the idle circuit which should be located under the silver welch plug on the carb; there are small holes under that plug which need to be cleaned out with the wire from a bread tie and then sprayed with carb cleaner nd then all holes blown out with compressed air. When you are shifting to reverse or forward for that matter do so with a forceful push on the shift lever; never try to "ease" it into gear. Good luck

 

[F_R]

Re: 1970 Johnson 20 hp problem

Before doing anything drastic, have you tried adjusting the carburetor's slow speed needle valve?

As for the shift, there are a number of possibilities there. Loose shift linkage is one. Worn out clutch dog is another. Why reverse worn out and not forward?? Well because forward was worn out and somebody just turned it around because they were too cheap to buy a new one. Then he found a ******* and sold it to him.

 

[Nick51786]

Re: 1970 Johnson 20 hp problem

I'm still trying to learn about all of this stuff , so where would the carburetor's slow speed needle valve be and how do I adjust it?

 

[AlTn]

Re: 1970 Johnson 20 hp problem

google...leeroysramblings...his writings on the 18 hp. models will be the same for your 20 hp. also, marineengine.com will have diagrams of your motors various parts...ebay usually will have some used OMC factory workshop manuals for your motor or outboardbooks.com

 

[Nick51786]

Re: 1970 Johnson 20 hp problem

Alright thanks for the help