Small Engines (Lawn Mowers, etc.): Honda engine loading up, burning spark, honda engine

Question
I just replaced a B&S with a Honda 6.5 hp on a BCS walk behind tractor mounted with a sickle bar head. Because of vibration at the sickle bar head BCS insists on a very slow engine rpm. The Honda is loading up with carbon fouling the spark plug and blowing out the exhaust. I assume it doesn't like running that slow. Any solutions? Carb. adjustments or hotter burning spark plug? I never had this type problem with the B&S.

Answer
Peter
Running at a low RPM will cause it to load up and foul plugs. What you may want to do is close the gap a little so that the plug is firing faster,which may not help if it doesn't get a hotter plug. You wont be able to adjust the low RPM Needle as it is closed off,if the B & S handled it fine so should the Honda. Is this Honda rated for equipment or for a tractor/mower??