It's been a while since I have contributed. I'll try to make this useful.
I do like the above link to the needle bearing conversion other than it is a tad out of reach of most.
This yamaha upgrade is great but for one thing. They sell it as a bolt on it is not going to stay in place for long.
Before I ordered it, I made sure my drag links were steel. They are and so the pieces can be welded in.
For better weld, see someone else with the patience to grind all the galvanizing off first.
First, obviously, disassembly. Now grind everything for welding. Install bearings and the original bushing. Use the old plastic thrust washer to take up the slack between the drag link and the steering arms. (see second picture) It is too thick. to get this the correct thickness, make up a block of wood with a plastic or wooden dowel the size of the center in the spacer. (see third picture) Then use this to sand the spacer starting on a piece of 80 grit glued to a flat something. It will take a few minutes. As you get close to the finish thickness, switch to 180 grit. This needs to be close because the bearing used is not designed for much side load. The tie rods push up and down as they are mounted at an angle. A close tolerance here will be one more rock in our foundation of tight, long lasting steering.
Now bolt it together, use a big washer against the bottom of the spacer so the collar is not being tightened into the aluminum. Assemble with grease, something light and waterproof, your not going back here again. I used Super Lube, silicone grease. Great product. Keep fine tuning till you get no slop and moves freely without resistance.
Now that that is done, disassemble one last time and paint.
Before final assembly, make a strap to tie the tops of the bolts together. This will insure the bolts will stay parallel to each other and not put that load on the aluminum drag link. (see first picture)
Also, this sits close to the motor, grind a taper on the motor side of the bearing cups. (see fourth picture)