80 hp merc no full throttle

[joelster69]

i have a serial # 6288214 80 hp 80s merc<br />last thing i did, was remove the carbs and clean em, installed a new diaphram(old one was ripped) ,now it starts right up,idles perfectly, and goes up to 8 mph, carbs seem to open fully but wont go past 8mph,cant plane,ill try new spark plugs, but i had 2 extras and swapped plugs all day , same prob, could air be getting in the fuel line? no smoke or unburnt gas ,tried 2 gas tanks new fuel,

 

[graddy]

Re: 80 hp merc no full throttle

Try puuting about 10 inches of clear hose between the primer bulb and fuel pump to check for air bubbles.

 

[dstuard]

Re: 80 hp merc no full throttle

I had the same problem and mine turned out to be the stator. High speed windings were bad.

 

[joelster69]

Re: 80 hp merc no full throttle

i was thinking low fuel pressure, but even when i try to squeeze the ball, the rpms stay below 2500, but i can see the carbs are wide open

 

[tmcalavy]

Re: 80 hp merc no full throttle

I just rebuilt/reinstalled the carbs on my Merc 500, and it ran like doodoo afterwards. My boat guy found two plug wires reversed and the timing was off. He plugged the wires up right (man I felt stupid), timed it and synched the carbs and dist. and the old girls runs faster than ever before. Total bill as $50. If you pulled the carbs off completely, it may need timing and synching again. Just my 2 cents.