I have a 30 hp Johnson with much increased power by means of getting more air into the crank case and an increased compression ratio.<br />To have the correct air/fuel mixture back I had to enlarge the fuel jet's hole to its maximum.<br />The result was a much better performance of the Johnson, which I first wasn't very impressed about.<br />The temperature of the motor is low due to a rich air/fuel-mixture and burning is free of detonation.<br />Especially the acceleration and max speed is much better then before.<br />Nevertheless the air/fuel ratio at maximum speed could have been a little bit leaner, but without being leaner at lower speed.<br /><br />Does anyone know, if the carburetor of the Johnson allows such correction ?<br /><br />I know from older car carburetors, they all had a so called air-correction-jet with a leaning effect increasing with load and revolution.
