i got my jets and shims in the mail today and i just had to go ahead and try it on my own. heres what happened, i switched from a stock #126 main jet and jumped up to a #130 main jet. i noticed the stock jet was a hex, but the one i replaced it with had a slot. i took out the needle and put in two .020 shims. when i measured the shims thickness i put two together and they measured .046 with my micrometer. handy being a machinist i can have access to tons of measuring equipment. according to google earth my average riding elevation is between 297-525 feet. all together the job was fairly easy and i got all worked up over it for nothing. thanks to everyone who helped me along the way. spark plug had a very light grey color with barely a hint of very lite tan before carb work. ill watch it. i also added a DG O-Series slip on exhaust, no noticeable popping in decel after a hard roll on the throttle. the TW seemed to like the change right from the start. after a few cranks the carb filled with gas and fired right up on half choke. choke off 10 secs later and good idle. thats right i said good idle.started down the road and the TW shifted through the gears much smoother and it felt the the power had been more evenly distrubuted through out the gears, and i did notice more power in the mid and upper gears. the bike seems to run a whole lot better! motor seems to sound alot smoother as well. what should i try next?