1968 johson 20hp help wont crank

boone68

Cadet
Joined
Jul 29, 2007
Messages
19
it wont start had carb rebuilt new feul pump and new point and condsers still wont crank set of new plugs and so on. does anyone know a easy way to set the points
 

Daviet

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Sep 24, 2008
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8,958
Re: 1968 johson 20hp help wont crank

You set the points at .020, with the rubbing block on the highest point of the cam that opens and closes the points.
Check compression while you are at it.
 

boone68

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Jul 29, 2007
Messages
19
Re: 1968 johson 20hp help wont crank

what posion should the timming plate be at
 

Daviet

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Sep 24, 2008
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Re: 1968 johson 20hp help wont crank

At idle, I don't think it really matters for setting the points.
 

boone68

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Jul 29, 2007
Messages
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Re: 1968 johson 20hp help wont crank

what is the lowest compression it could run at are what is a good compression average
 

flintcreek

Petty Officer 3rd Class
Joined
Apr 19, 2009
Messages
90
Re: 1968 johson 20hp help wont crank

I have had 10 hp motors run good with 60 lbs compression. On a 20 hp I would hope to see at least 60 plus, but the main thing is both cylinders close to equal (compression gauges vary quiet a bit from one to the next) so don't get too hung up on a number. Attached is a good link on how to set the points and tune up.

http://www.outboard-boat-motor-repa... 5.5 HP 1954-1964 Ignition System Tune-up.htm

Flintcreek
 

boone68

Cadet
Joined
Jul 29, 2007
Messages
19
Re: 1968 johson 20hp help wont crank

i have set the points and i have around 65ib of comperssion and it still will not crank any more segustion please help
 

Daviet

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Sep 24, 2008
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8,958
Re: 1968 johson 20hp help wont crank

Try squirting some fuel into the carb and see if it will fire.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: 1968 johson 20hp help wont crank

What do you mean it will not crank? It will not turn over or it will not catch and run? If it's not running, verify good spark. Use a spark tester.
 
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