On that first picture are those your hubs with thee allen screw in them? If so, I don't know if those will hold together under a ton of stress.
Still gonna weld those. Not planning to weld the circumference but four solid tacks opposite the bolts. The hex cap screws that we used are harder than grade eight bolts. Still you are right, likely wouldn't be strong enough if the thing actually hooks up and pulls.
Worked a bit on the fenders today, not a lot, but cut them in half and gave some thought to what i'm going to do, photos below.
first gonna add 8" of sheet metal to widen fender assembly
sorry they are sitting on there a little crooked looks a bit odd don't it.
second gonna finish off front part of fender assembly to lower seat into fender assembly to original height.
i'm going to make the new center piece of the fender assembly easily removable to get to the pulley and what not. Can anybody recommend a place to get a compact type seat, looked all over for one not happy with any so far, leaning towards a cart seat but my goodness the ones I found are quite pricey. I've seen one on here that i like but can't remember where.
http://www.jackssmallengines.com/gokartseat.cfm.