I have a 1990 sno sport and have been battling with a bog under acceleration ...long story short the carb is clean and I jetted it up to 132.5 from the stock 97.5 and it pulls fine and runs well. So I think there's a air leak either crank seal or carb boot. Boot seems fine. Can I replace the crank seal without taking motor apart? Can I even get a seal and head gasket still?