Why is my timing advanced

boomboom

Cadet
Joined
Sep 11, 2010
Messages
11
J70TLEIE 1991 johnson 70hp

Motor runs good and is reliable now, but idle is still rough. when i checked the timing the screw is all the way in. A boat shop told me thats probably because the motor is "worn out and wouldnt idle." Thats my problem if i set it at the 4degree Atdc it wont idle. Compression checks even at 90 pounds(is this enough and if not how should i raise it). Carbs have been cleaned several times. New champion plugs .030. New fuel lines. Flushed gas tank. No air in fuel line sight hose. Replaced coil 3 due to occasional lack of spark.

its a minimum of $325 dollars to have it checked out here which isnt happening so im pullin my hair out here!! Thanks in advance guys.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Why is my timing advanced

Try giving it a good PROPER decarb and see what happens. You may just have some stuck bottom rings on your pistons which will effect idle yet you can have good compression.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Why is my timing advanced

Which screw are you refering to? The one in the throttle arm?
 

boomboom

Cadet
Joined
Sep 11, 2010
Messages
11
Re: Why is my timing advanced

Which screw are you refering to? The one in the throttle arm?

Thanks for the reply. Not the throttle cam, The time cam...its just below the flywheel. Screwed in all the way takes up the slack in the spring = advanced timing about 5 btdc at idle.

Ill try the decarb this week end. Ive done it before but didnt let it soak.
 
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