Is the gasket between the carburetor and block the correct one ?----Some have 1 wee hole for the crankcase PRESSURE pulse.----It must line up correctly !
What are the compression numbers today ?----Water pump impeller replaced ?-----Overheat horn tested ( if equipped ) lately ?----Spark on each cylinder that jumps a gap of 3/8" or more ?
Some do not understand good advice.----Check the flywheel key.----Costs nothing !-----You can not detect a sheared flywheel key by just removing the nut.-----You can not find a sheared key with a timing light either.
Do a compression test.-----The original head gasker were not the highest quality.-----New gaskets are improved with Sierra being the best deal.-----And does spark jump a gap of 1/4" on a test device on both leads ?