i used up about 6 gallons / maybe 700 miles, i know dennis, saidwe should have 1000 before installing high performance. were you able to get the get the 4700 muffler. cedarburg outdoor is the best place to buy parts for tanaka he can direct ship to you from the distributor. 47 muffler cost 45 + shipping. i bought my 40 engine from them, cost 315 with shipping. talk to adam. if you did get the 47 muffler, did it have a affect fo performance? how about noice level. i tried to look at you post and thread. i did not see any about the swap.
what upgrade have you done on your tanaka so far.
did i read it right that you live in chino. i live in san diego