90 johnson gt 200 timing

nootdaddy

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Jul 28, 2010
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i'm tryin to adjust my timing and tryin to figure out what the spark timing adjustment does and what the dwell spark timing adjust does any input would be appreciated thanks in advance!!
 

Dhadley

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Joined
Feb 4, 2001
Messages
16,978
Re: 90 johnson gt 200 timing

On that motor you can adjust the idle timing and the wide open timing. Timing is measured in degrees. The spark plug will fire at so many degrees either before or after that piston reaches top dead center. When we say a motor is set, for instance, at 18 degreees at wide open, that means the spark plug fires at 18 degrees before the piston reaches top dead center on that stroke. The less the rpm, the less advance the plug will fire at.
 

nootdaddy

Recruit
Joined
Jul 28, 2010
Messages
2
Re: 90 johnson gt 200 timing

ok i'm not sure of the procedures so please can you explain in detailed hot to do it and which adjustment bolt is for which one thanks!!
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 90 johnson gt 200 timing

If you are not well versed in making these adjustments I'd strongly suggest paying a pro to do it. Making a mistake can result in a damaged piston or worse. The idle timing isn't that critical but setting the wide open timing is very, very critical.
 
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