briggs & startton 12 hp?

Not sure about your engine specifics, but it sounds like you are refering to a flywheel type thing?
To remove a tight flywheel on one of these I would very rarely just tighten a puller as it will pull the bolts / threads out.
The way to do it is tighten the puller reasonably tight, then give the centre bolt (on the puller) a very sharp tap with a hammer, usually this breaks the taper seal between flywheel and crankshaft.

Good luck.

Paul
March 2010