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HELP 65HP Evinrude 1973 model 85393M wide open throttle issue

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btvanmagn

New member
OK, so here it goes.. As you see above this is a 1973 85hp evinrude... Engine runs, a little tough starting, but runs well... issue is that when I push the throttle all the way forward, the engine does not get the boat up on plane.. all cyl are firing now... good comp in all 4 cyl... carb has been cleaned, but not rebuilt, but as I read in other posts sometimes if it is a carb issue, then if you pump the primer bulb, the engine will serge to life... Well that is not the case here.. I have pumped that while the engine is running, and that does nothing to help.... Much of the ignition system has been replaced now, but I have not gotten under the flywheel, as I am not 100% sure I want to do that while it is in the water... Any thoughts??
 
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Is the 65hp enough for the boat it's pushing? Do you know what rpm you're getting at WOT (could be the wrong prop for your setup)? The "pump the primer bulb" test will let you know if it's a fuel pump problem more than a carburator problem. Is this a new problem?
 
Yes Sorry this is a 85 HP... I fat fingered the hp on the title... This engine came with the boat I bought... of course it had bad gas in the tank etc. which I think I took care of it all .. as for the prop yes it is the right one... The rpimer bulb does nothing to the engine when I pump it, so it seems that it is a fuel issue in the carb... When I spray carb cleaner in the carb ports while running it does pick up some....
 
Is the timer base advancing fully? Sometimes with age, that delrin ring gets gummed up and won't allow the timer base to move freely. That creates a major loss of power. Also, are your throttle plates syncronized with each carb?
 
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