Ahhh, don't do that Lynn. It's a great runner for the outdoors, a go anywhere dumper without getting hung up on a twig or a sandy knoll.
My Mammoth hauled out the first two cubic yards of dirt from my basement in the summer of 2005... I wore out the rear driveshaft, but other than that, it's still going strong!
If you're still using the kit stock motor, then a better choice would be Willy's WWR truck puller motor (approx rpm 8000) or an Integy motor of approx same rpm on 7.2v.