When I pull the throttle my TB spits and sputters at first and then starts to run fine (it will go 45mph). This isn't very noticeable when kids are riding on the dirt roads (no load), but if you start up a steep hill from a stop it can not get revved up enough to get enough power to go up.
I plan to put a new plug in and run some Seafoam through it this weekend, but not very confident this will fix.
Any ideas what else I should try?

 

make sure your air filter is clean, if it is then i would try going down a size on the pilot jet

 

very true, i had a similar problem and it turned out to be a dirty air filter

 

Thanks, but I cleaned the air filter already with no luck. So much for the easy fix.
Is there any adjustment on the carb for the low end?