The Milwaukee 8, the reason why I traded my Road Glide Custom in for the F6B was because it was frying my balls at idle with the 103 c.i. engine so the new 107 should really put it on broil. Indian and Harley can duke it out with the cubic inch war, without any consideration for thermal evacuation, till they kill themselves I'll be nice and cool on my "B". If I'm not mistaken you have to pull the tank off on the new motor to change the plugs - genius.