Hello, I have a 1982 Bobcat 642 with the Ford 1.6 liter engine. The machine starts and runs good with decent power, but when starting the machine it is fine at first, but about 5 seconds after starting it starts to smoke pretty bad. I checked compression and it is about 110-120 psi on all cylinders. It is also getting some back pressure on the oil fill cap and starting to blow the front oil seal. Could this possibly be caused by cylinder washdown if I am running rich (carb or ignition adjustments) or is it likely needing a top end rebuild? If it needs an overhaul is it better to do this right away or wait until it dies? Thanks for ideas