Hello everyone. I have a 1973 Evinrude Lark 50hp, model 50573, electric shift on an old MonArk boat. Got the motor running for the first time in a few years a month or two ago by Originally putting in new spark plugs. But I experienced the boat not getting up to speed or plane, and bogging down at full throttle. I then found that fuel pump was leaking so I replaced it along with fuel lines all the way to the tank.
After that, the engine would sound smooth and clip at a good pace under low speed but the bogging down would still occur at full throttle; but to a lesser degree but still couldn’t get to plane. I noticed the plugs were wet and blackish in color so I cleaned them up and slightly adjusted the rich/lean idle dial on the outside of the motor from “rich” about 1/8 inch to lean.
After that I let the boat sit about a day and took it out. The engine ran like a dream. It got up to plane, capped about 24-25mph and ran perfect at low speed and full throttle.
I then took the boat home, and headed out again about two hours later. This time when putting the boat in the water, the engine seemed to be flooded at first starting and took a bit to get going. Once moving, the engine wouldn’t get up to the same speed or on plane like it did a couple hours earlier. Any thoughts on what the issue could be would be greatly appreciated.
After that, the engine would sound smooth and clip at a good pace under low speed but the bogging down would still occur at full throttle; but to a lesser degree but still couldn’t get to plane. I noticed the plugs were wet and blackish in color so I cleaned them up and slightly adjusted the rich/lean idle dial on the outside of the motor from “rich” about 1/8 inch to lean.
After that I let the boat sit about a day and took it out. The engine ran like a dream. It got up to plane, capped about 24-25mph and ran perfect at low speed and full throttle.
I then took the boat home, and headed out again about two hours later. This time when putting the boat in the water, the engine seemed to be flooded at first starting and took a bit to get going. Once moving, the engine wouldn’t get up to the same speed or on plane like it did a couple hours earlier. Any thoughts on what the issue could be would be greatly appreciated.