by locking up the clutch and locking up the rear tire, you are only putting more stress on the chain, because it is actually the chain exerting the force on the tire to stop it, therefore making the chance of breaking it more likely...not a great idea
i bought my 5 hp briggs, with a clutch, that runs fine, and still does, bought it 2 years ago, for 15. Car shows are the place for used small motors, im tellin ya.
They have two of the parts i was looking for, and i dont want to pay 200 for a non comet torque converter, new or old, would rather buy a quality used one. None of their parts work for briggs other than the filters (maybe)