First off, I am new to Blasters, have some 2 stroke experience and lots of experience with 4 strokes. I have done some reading here to familiarize myself a bit. Borrowed a '98 Blaster from a friend for my g/f to use while I rode my KLR. She bombed around on it for about 1/2 hr when it quit. Fast fwd...tore down and found piston failure which shows classic symptoms of a lean air fuel mixture. Exhaust side of piston is melted with a hole burned through top of piston toward exhaust side. Obviously the top end needs to be rebuilt, but I would like to shed some light on the cause of the failure so I can prevent it from happening again. Neither of us knows too much about the bike, but here are the details as I can tell: 1) what carb do you have??? Mikuni--measures 28 mm on engine side 2) What type of aftermarket exhaust do you have? Stock AFAIK 3) What type of airfilter do you have? foam 4) What kind of air box set up do you have?? stock with 8--1" holes in lid 5) What size pilot jets are you using? 32.5 (stock) 6) What size main jets are you using? 230 (stock) 7) What needle position? 2nd from top --It was a 50F day, and we are approx. 900 ft above sea level --Spark plug was a BR9ES, which is 1 number colder than stock I believe --Checked the intake boot closely and it looks ok. --Oil injection is hooked up and seems to work, however I did add approx 200 mL of oil to a full tank of fuel "just in case". After doing some reading, I now realize that wasn't smart since adding more oil actually leans out the A/F mixture. Here's my plan of attack: 1. Over bore cylinder with new piston etc, flush debris from bottom end 2. Install correct spark plug 3. Leak test to verify no air leaks 4. Try a larger main jet...maybe 240 or 250 and lift the needle 1 notch 5. CHECK SPARK PLUG COLOUR OFTEN! Also I'm debating on whether to keep or ditch the oil injection. Is it known to be reliable? If I decide to pre-mix, what jetting is recommended. Also how much ball park is this thing worth with a good engine...has steel rims with some dents, good tires, plastics are not cracked, seat is not torn, needs front brake shoes...fair to good cond in my opinion...worth maybe $1000? Any ideas/advice are much appreciated.