I have a 5hp b/s model 135202 and the start cord jerks back out of my hand BIG TIME! The flywheel key is a perfect fit. The original was a perfect fit but I put a new one in just to be sure. I removed the crankcase cover and the flywheel gear and the crankcase gear timing marks are aligned perfectly. I replaced the carburetor with a new one. I set the coil air gap, it was to close. Nothing is working. I still have the same problem. This motor is on a tiller not a mower.