Look here RockyMtnPrincess, you uneducated construction worker, Can't you read!?? he is on clicker 6 already and said that he already took it in twice, I'm sure that when they looked at it all they did was check the motor (like they usually do when you say it doesn't run right) and they can't exactly test drive it now can they?
I'm sure RkyMtnPrincess it's in "Safe Mode" HAHA LMFAO!!
I'm sure you also believe that your sled has a burn chip in it too!!
anyway I've already wasted enough breath on you, so anyways,
Yea Johnny B, all you have to do is pull the Main spring out and check it to a new one, you don't even have to buy one unless it looks off, quite easy job and only takes about 20 mins and a few tools. but I am sure it will be weaker and shorter, then when you install the new one you will be back up to using clicker 2 or 3.. as far as the fuel issue, people always overlook the simple, so it may be a broken reed valve and pushing fuel around like crazy, but it really sounds like you have two problems. are you using full synthetic, that tends to build up a little more as it doesn't burn off as easy.
the motor may be fine, so the shop you take it to is either like RkyMtnPrincess (incompitent) or you may be overdiagnosing sysptoms which are normal (plugs with a little carbon on them, and a slightly wet airbox doesn't mean horriable issues)
if its getting up to rpm and speed on the trail like normal I doub't its the engine.. but hey, it would be worth looking into.