joe@zinfandel.UUCP (03/16/84)
#N:zinfandel:4600021:000:786 zinfandel!joe Mar 14 08:40:00 1984 Hi. I just got my monthly fix of motorcycle magazines in the mail, and found an article about run-in procedure. Apparently the best technique is to alternate short periods at moderate engine load, like half throttle acceleration up small grades, with periods of coasting. The loaded phase forces the rings outward against the cylinder walls causing the rings to seat well and avoiding heavy heat build-up because of the short duration. The coasting phase pulls engine oil up while the engine still turns by engine braking, which both cools the pistons and rings and carries away the metal residue caused by the seating process. Also, if an oil is too thick it can float the rings on too thick a film to allow good seating, allowing a varnish of burnt oil to build on the ring faces.