Mercury 850 won't run in water

hoffmanuno

Petty Officer 3rd Class
Joined
Jul 23, 2006
Messages
82
I recently rebuilt the engine and carbs on an old 63 850. When I rebuilt the carbs I never adjusted any of the mixture screws, just replaced the seals and reset the new floats. It ran fine in my driveway with the mickey mouse ears on, accelerated smoothly in forward and reverse and revved up well. I idled it for my break in period in a drum filled with water and a hose so the rings are seated. My problem was that once I got it on the water it wouldn't throttle up much over idle even if I moved the control lever all the way forward. After a few minutes it started running slower and slower and eventually died and wouldn't restart until I got it towed back to the dock and finally opened up the butterflies on it all the way. Any ideas? It is getting fuel to the carbs by the way, I pulled the connection line on the motor side.
 

corm

Lieutenant Junior Grade
Joined
May 12, 2000
Messages
1,241
Re: Mercury 850 won't run in water

Hi,

Just a guess but do you have spark on all 6. It sounds like your running on 3 to me.
 
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