The new yoke assembly I got from Bill Gun has a softer tire on them. It seems to ride over stuff better. Order form Bill or look around in a hardware store for casters. The wheels come in all sizes. You might have to buy the caster just to get the wheel you need.
Yes you can tip the deck up in reverse! We could call it a feature.
I noticed the same problem with going in reverse if the deck catches a tree root the right way it will tip up.
Any body have any mods for the front casters they seem a bit hard for areas with lifted sidewalks or tree roots. It seems like a small air tire would allow a little more give.
Agreed with the roll pin breaking, but mine broke off where the inner sliding part joins the spherical (is that right?) bearing at the mower end. I'm not too surprised at that, but what is a concern is the mower deck tilting up so easily when in reverse.