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1989 mariner 50hp carbs

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Michael_xr8

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Hey I have a 1989 50hp mariner with twin carbs, I have ordered a manual but can anyone tell me if the carbs are meant to run at the same time? Or is one a secondary?
 
They both work the same way.------------And the top carburetor on a 4 cylinder only feeds fuel / air to the top 2 cylinders.------No such thing as a " secondary " on your motor.
 
Ok should have said it's a 3 cyl but I'm sure they work the same way, I might do a comp test before anything else cos I cleaned the carb with carb clean and it would nearly die if I sprayed a lot in the bottom carb but wouldn't do the same in the top carb
 
On a 3 cylinder the top carburetor feeds # 1 and 1/2 the supply to # 2.---------The bottom carburetor feeds # 3 and 1/2 the supply to # 2 cylinder.-------Start with a compression test.
 
Yeah thought that was the case it runs fine and everything just doesn't idle like I think it should so I will comp test then spark test, last time I comp tested it was ok. Will post test results tomoz thanks
 
Are you " cleaning " the carburetors by spraying in some " mechanic in a can " while it is running ?-----Have you looked into adjusting low speed mixture needles ?
 
Those are tricky carbs to adjust (on that particular motor), and the adjustment is CRITICAL to prevent bogging when you open the throttle. I use an infrared temp gun on the base of the spark plugs when I do them. The goal is to get all three plugs running the same temperature, around 90 'F (believe it or not). I then add 1/4 to 1/2 turn OUT (CCW) to the adjustments to prevent bogging, and live with the idle.

Jeff
 
Haven't adjusted anything yet as I'm still waiting on the manual, the idle is the annoying part cos if I putt along and try stop at the jetty by reversing it can die and I look like an idiot when my boat hits the jetty. It doesn't bog at all tho.
 
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