If your engine is mounted with the flywheel forward you should have a little pull to the right. Don't understand why it would pull to the left. My Howard pulls just enough that if you take your hands off the wheel the boat will begin to turn gradually. If I nail the throttle it will pull harder, depending on which prop I am using. The three blade will pull more than the two blade. With the two blade once I get wound up it doesn't pull either way. Usually the boat will turn better to the direction of the pull.