Rob,
You don’t want the throttle to hit the stop at the engine. Full throttle is adjusted with the stop on the floorboard. The last few % of throttle opening is insignificant for the performance of the engine. Bad things happen if you use the engine stops.
If you think there is way too little throttle, check the accelerator cushion. The internal rubber cushion can fail yet the housing will let you get part throttle. Check
this link.
Best,
Grady