I just bought a 1986 2 stroke long shaft outboard 50 hp and have been working on it for a while now. It has 4 spark plugs and 2 carbs. I have put a new starter motor on it, new spark plugs and replaced one carb. The motor doesn't run well and it sounds off. It starts right up but it seems like its only running at half power. It wont even put my 15 foot trihull (1966 sportscraft) on plane and when i push the throttle all the way down it dies. I have put in a new fuel line and ran a can of seafoam through it. When I put a pair of muffs on and run it out of the water, the engine throttles up and it sounds much better. I can push it to full throttle and it doesn't die.
I have tinkered with the jet screws on the carbs and checked to see if theres any air blowing out of the carbs which there isn't. Water comes out good from the cooling line and the lower unit has new oil. The solenoid is also new. This problem only seems to happen when i put the boat into the lake. It sounds much better when the prop doesn't have any resistance. All four of the plugs have good spark.
Background: This is my first boat that I got for a quarantine project. I repainted the whole boat top and bottom and put new fiberglass in the bilge and put a new floor. Im trying to get this motor working before I start college but I dont know what else to try.
I have tinkered with the jet screws on the carbs and checked to see if theres any air blowing out of the carbs which there isn't. Water comes out good from the cooling line and the lower unit has new oil. The solenoid is also new. This problem only seems to happen when i put the boat into the lake. It sounds much better when the prop doesn't have any resistance. All four of the plugs have good spark.
Background: This is my first boat that I got for a quarantine project. I repainted the whole boat top and bottom and put new fiberglass in the bilge and put a new floor. Im trying to get this motor working before I start college but I dont know what else to try.