I have a TM40 on my DR650, and apparently the accelerator pump isn't working. The carb itself works OK, but the throttle response has dropped-off. Hopefully it's something simple like gas-gunk in the jet, but I dunno. Is this a common problem fixable on my end or do I need to sent it off? How complex/finicky is the pump? Just looking to steepen my learning curve before I tear into something of which I know little. Thanks for reading!