me.. i think at the very least you should get the cylinder bored/honed, and the valve seats at the very least lapped, if not reground. if you look on ebay, you can get pistons and rings pretty cheaply brand new.or just go with and 850 kit from cycle x...pretty cheap! but then you will need a cam. check for any stripped screws and bolts...and check your oil pump to see if the propellers are scored...meaning it needs torn down too. i had to buy 4 oil pumps before i found one worthy enough for my rebuild. get a digital caliper and check your cam lobes and journals. check the chain tensioner and all other parts for wear, tranny and chains...all that shit...and start scrubbin....toothbrushes and dishbrushes and alot of brake clean or your favorite engine cleaner. take lots of pics as you go and get the manual downloaded so you have it...it is pinned at the top of Q&A