Bought basically the same sled from a well off older man who had a pair of these sleds. Perfect shape. He had the habit of starting them up all summer long and let them run for awhile. Sounds good, but it caused some rust to develope on the crank bearing, and I lost it last winter at around 6500 miles. Totally rebuilt it, had the crank rebuilt, pinned and welded. Machinest said he has seen a ton of cranks come thru, and he says people get carried away with summer maint. Too easy to get condensation in the engine..Said to start it up, get it hot, choke it until it dies to get gas/oil in the crankcase, pull plugs, spray cylinders down, put plugs back in and leave the goddamn thing alone until fall. Top the tank off with fresh gas, then drain it out in the fall, put the gas in the plow truck, and put in fresh. (been doing this for years, no troubles) I love this engine, sounds really cool, plenty of snap, and my son got reallly good gas mileage with it.You will love this sled,....good luck.