Join Date: Aug 2005
Location: North Augusta, SC
Take off the clutch cover, oil pan, oil cooler, oil filter. Flush the motor with something like mineral spirits or something similar to that. A parts washer is a good thing to have to clean these things and you can use the fluid they have in them to flush the motor out.
Clean the oil pan and visually inspect the oil screen in the oil pan and rinse it out good. Pull the clutch out and clean and soak them in some oil. Remove the oil cooler and using the parts washer set it so it runs the fluid through the oil cooler to get it cleaned out, then blow it out with some air, tie wrap the handle down on the air blower from a compressor and set it up to blow in the cleaned oil cooler, say 5-10 mins.
After putting everything back together, fresh oil and filter, crank it up and let it idle for about 15 mins, shut it down let it cool and change the filter and oil again. It wouldn't hurt to do this at least 2-3 times; buy the cheap filters for this. Last oil and filter use what you would normally use, and put everything back together like new or used plastics and stuff and ride.