WOW!..and you tried running FOUR STROKE RICH LOL..man i dont know what to tell you anymore except dont give up on the company just cause you got a OLDER motor that may or maynot have a recall on it!...lol....I DEFINENTLY GIVE YOU A 10 THUMBS UP FOR TRYING!..$513 DAMN LOL....I WOULD HAVE JUST BOUGHT A NEW 1 AND TOOK THE LOSS ON BUYING A USED ENGINE THAT SOMEONE TOLD YOU ONLY HAD 1 GALLON ON IT!....AND THERE ARE ALOT OF GUYS OUT THERE THAT CAN MAKE A OLD PISTON AND SLEEVE LOOK BRAND NEW!...AND THEN PINCH IT AND SELL IT SAYING IT ONLY HAS 1 GALLON ON IT!... check out RcRenew.com he is my buddy and does piston and sleeve pinches and RENEW'S the shine on a piston and rod for you!...just look at the website so you can see what can be done to an old piston to look new!....the seals on the carb PLAY A BIG PART IN THE TUNE!....so if you havent tried that yet then dont give up!...cause it will upset you when the $10 in orings fixes it...after youve thrown $513 at it already lol.....those seals are BAD! they had a tendency to break down without the USER knowing it!...thats why they were changed in the new models!