With a 6 in pulley on the engine, 2 on trans, a governer bypass and 21 in tires and I got to 50. WAY too fast for a mower with stock steering. Deathwish really.
Pulley swapping that transmission won't help you go faster, it's just going to nuke the trans because you're spinning the pump inside too fast. Best bet is to go get a 5 or 6 speed trans from another mower.
This one ended up with one of my friends, I kept the deck and the blower and he bought the tractor itself. it's currently sitting waiting for a pulley swap and some tlc, (battery and ignition switch). Pretty sure he's planning on throwing some atv tires on the back as currently it's got rotted...
Clutch is a separate unit like said. If you really want to see I'll pull one of those engines apart next time I'm home. But all three yellow plugs are the same exact thing, and the clutch is EXTERNAL and doesn't require oil like that.
I just grabbed the one I could find on Thingiverse, as in why it's linked. Testing to see how it does, currently the point is to test if the print itself will hold up, can worry about stuff like that later. Free printing after all.
Just as a repeat, all one big sump, should just be 30 weight motor oil. Three yellow plugs all lead to the same spot. And it's also a centrifugal clutch.
Part of being at school for engineering is free prints. Remembered seeing something about a 3d printed adapter so I figured I'd try it. (Budget)
PLA with 100% infill, I'm aware of the strength concerns and am trying because free prints.
One suggestion from me. That throttle cable would work better if it was parallel to the frame, no sharp turns as that could cause it to drag and possibly not return and also wear the cable.
Heres some of my adventures lately, (4 hrs ago) went for a ride in my buddy's CJ5 and broke down. Lost a vacuum line, but in the process met a guy restoring a CJ 3A.
32s, dont know the lift and the questionable buick 231 v6.
Live axle is probably the best route. If you do mobe the engine and keep it one wheel peel you'll be burning through tires.
Another bonus of the live axle would be better brakes. Especially with the 7 year old. I know when I was that age I liked going fast and good brakes help.
Also I'd...