Finding year model of Johnson 20

[rickandtinawms]

I have a Johnson 20 HP, Model #20R73 A, Serial #E3763619.

How can I find the year model and the correct fuel/oil mixture?

Thanks!

Rick

 

[Xcusme]

Re: Finding year model of Johnson 20

Welcome to iboats Rick,

You have a 1973 20HP Johnson. Your fuel mix is 50:1 (16 oz.TCW-3 oil to 6 gallons of gas)

 

[rickandtinawms]

Re: Finding year model of Johnson 20

Thank you!!!

Its my Dad's old motor, and he said it runs great, but won't stay in forward gear. I've not run it yet to know for sure. Is that a common problem?

Rick

 

[Xcusme]

Re: Finding year model of Johnson 20

Not so much common, but can be caused from a couple of reasons. A miss adjusted or coupled gear shift rod OR a bad dog gear in the lower unit. Slow shifting can be the cause of a bad dog gear. Shift smartly into and out of gear, and keep the motors RPM's low when shifting.

 

[rickandtinawms]

Re: Finding year model of Johnson 20

Thanks again! I may ask for help again when I get it running if it is indeed a problem.

If it is a problem, will it damage the motor further to operate it in that condition?

Rick

 

[Xcusme]

Re: Finding year model of Johnson 20

No, it won't really do any damage, the gear teeth are already rounded over. It will tend to be a bit of a surprise when the gear slips. It will sound like you hit a log, as the gear disengages and then reingages. The only solution is to back off on the RPM's, don't push it too hard. The real solution is to replace the worn gear(s). You'll need a service manual to walk you thru the repair.
Feel free to ask any questions you may have. The guys , here at iboats, are a good bunch and always willing to lend you advice.

 

[F_R]

Re: Finding year model of Johnson 20

Well, it is a bit of a strain on the shift linkage when it jumps. Keep it up long enough and it can cause damage, like knock the little lever loose on the inner end of the shift shaft.

 

[rickandtinawms]

Re: Finding year model of Johnson 20

What a blessing to be able to get help! Thanks to all.

Got it running, but doesn't want to idle. Any suggestions?

Rick

 

[tashasdaddy]

Re: Finding year model of Johnson 20

if it has been sitting unused, the carbs probably need to be dismantled, soaked in carb cleaner, blown out with compressed air, then reassembled with a rebuild kit. the the carbs adjusted. with the engine in the water.

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