Re: 1966 80 horse evenrude
I will ramble with my thoughts about this based on been there and done it:<br /><br />Which cyls are not making power at low speed...same carb or both carbs? If on one carb at least you know to work only on that bank. If on both carbs I'd say both rebuilds were done wrong OR it not at all a carb problem. This leads to fuel delivery or electrical. Have you played with the adjustable mixtures? Reeds are delicate so they may be the problem too.<br /><br />The motor should still run fast (but dirty) without the tstats in so I don't think cold is the problem. It may work that way up north in really cold water but not where I live in warm climes. <br /><br />This is an old motor, have you replaced the pump diaphram? Have you pumped the bulb when the motor is at full throttle? Check bulb, lines and connectors for air leaks.<br /><br />Is the motor backfiring...this is a sign of electrical issues. No backfire is generally fuel related. <br /><br />Getting spark at the plugs doesn't mean it is firing hot enough under compression. That motor has 1 external coil right? If so, any $20 automotive coil will work...just check the motor for a resistor or non resistor coil. Your motor may have red/wht stripped resistor wire instead. Just disconnect the resistor wire and use a coil with resistor if you want. I ran a 1965 Johnson 75hp this way 100s of hrs. <br /><br />The spark plug wires are SS and the wire rarely goes bad, it's the rubber and connectors. Check for cracks and use high temp silicone to seal if you don't want to spend big bucks. Distributor cap and rotor may be cleaned up but I've never had that last long.
