New guy with a new hobby-Yerf 3002 rebuild
 

I've been fixing airplanes and guns for the past 30 years and decided I needed something different. Looking for something to rebuild with my 11-year old boy to teach him how to use tools. I came across a Coolster 125 Challenger and Yerf 3002 frame. The Yerf is the better of the two and we are going to start there. Somebody in the past put on Douglas polished aluminum wheels and some huge tires. Unfortunately the front end is just WORE out with the spindles trashed. Somebody had tried to reinforce the spindles in the past but probably got tired of rebuilding it. I also think there was a bigger motor on it but removed it and the Comet TC and put back the original (and pretty wore out) Tecumseh engine on it with a CC instead of the Comet TC before selling it to the guy I bought it from. The 4" band brake looks a little anemic for the large 25x12-10's in the back. Up front there are 23x7-10's. So the question I have is if I want a lot of torque for climbing hills will a Predator 6.5 with a 30-series TC do the trick for turning the rear wheels and hill climbing or should I go to a 8 or 13 HP motor with a 40-series TC? Will a drum brake work or should I go hydraulic? As far as the front end goes I'm thinking of ordering a 3002 replacement spindle/arm and maybe reinforcing it with some gussets, etc. Or taking a gen 3 Spiderbox spindle and making it work on this. I also think the steering linkage is a bit on the puny side and am wondering what direction to go to make something a bit stronger. What do you guys think? I'm new to this karting so I'd like to avoid expensive mods that won't work. Thanks

you'll just throw a lot of metal and time chasing those spindles and tie rods. likewise the single a-arm geometry is pretty poor because of camber change. have some fun and pop a spiderbox front end on it. gonna take some work.

I personally think the challenger is the better of the two.