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1998 Jonson 70 hp - No Start at Closed Throttle

M

MLaBounty

New member
1998 Johnson 70hp. It will run, but not with the throttle totally closed. When it runs with the throttle slightly open, it’ll stall below 1,100 RPM. I’ve been attempting to adjust the carbs per the method included in this link:

blog.marineengine.com

Johnson Evinrude Carburetor Adjustment – by Joe Reeves

Johnson Evinrude Carburetor Adjustment - by Joe Reeves
blog.marineengine.com blog.marineengine.com

But still cannot seem to get it started without the throttle slightly open. Currently, I have adjusted the throttle cam to hold the butterflies of the carburetors slightly open at idle (it’s the only way to get it to run). Also, when put in gear in the water and under load, it will stall out unless I quickly open up the throttle. Any ideas for the cause? See below for the work I’ve done on it so far:

-Rebuilt the carburetors (replaced gaskets, floats, & needles
-Replaced the rectifier
-Adjusted the timing to the spec at idle & WOT
-Replaced the fuel pump with a master tech premix pump
-Disassembled and cleaned the primer solenoid
-New spark Plugs
-Compression is 100, 100, & 90 on the bottom cylinder
 
I would remove cylinder head for inspection.-----Head gaskets are cheap in the big picture.-----The 90 PSI is a concern.----Throttle must be slightly open for a cold start.----And primer solenoid does nothing once motor is running.
 
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