1986 yamaha 50hp outboard breaking up limited throttle

vrrado90

Recruit
Joined
Aug 9, 2009
Messages
1
hi all.i have a 1986 50hp outboard that i totally rebuilt.brand new fuell pump cleaned carbs and all fuel lines new fuel filter.it starts fine it ran first day for an hour or two great ran really good.the next day it ran the same this was the first day i really leaned on it for a whole hour at 3/4 throttle the warning buzzer sounded.i shut it down to check vitals all okay.i then restarted fine no buzzer but runs like crap.it runs okay at half throttle but breaks up and surges at wot and under heavy load and will not go over 4800rpm.to me it sounds like cdi box any one have any ideas?
thanx mike
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: 1986 yamaha 50hp outboard breaking up limited throttle

I've had deteriorating foam hood liners make fine bits that fit through carb bowl vents and clog jets.
 
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