Small Engines (Lawn Mowers, etc.): crankshaft pulley, crankshaft pulley, crank shaft

Question
I have a new 205 cc Briggs engine with 6:1 gear reduction. I am replacing the older engine on my two wheel tractor. My question is about the crank shaft pulley. The crank shaft pulley that came off he old engine fits the new shaft fine, however it strikes the gear reduction housing lightly. Would it be ok to put a washer behind the pulley as a spacer, to keep the pulley from striking?

Answer
A washer should not be a problem but will the washer cause a mis-alignement with driven parts such as a belt or chain?   I am betting the slight mis-alignement will not be a problem.

You could also cut or grind the pulley shaft just a little to keep the pulley from rubbing the gear reduction.

Eric