Ultima Pro Restoration

[terry.sc]

Got to be the worst ever ball diff design, using hard steel plates rather than separate replaceable diff washers. You need part WBD-1 to repair it. Unfortunate that teh rerelease parts don't fit unless you replace the whole gearbox which isn't cheap.

I didn't notice back then but the shock tower is different than stock. Not sure if that was a mistake or supposed to be an improvement. I'll try to use it as is but the link connection holes are a bit different, this will cause some different dynamics, the mounting holes to the bulkhead are correct. Not like I'll be going to any nationals anytime soon.

The top shock mount is the Kyosho standard tower for fitting gold shocks. The lower mount is a third party item, the bottom is shaped like the original Ultima alloy shock tower for the red shocks, made taller to fit gold shocks. The top is shaped like the JG towers, but the lower section is different on a JG mount.

[Swath]

Got to be the worst ever ball diff design, using hard steel plates rather than separate replaceable diff washers. You need part WBD-1 to repair it. Unfortunate that the rerelease parts don't fit unless you replace the whole gearbox which isn't cheap.

Can't argue with that assessment. I was looking at the breakdown drawings of the other designs and thought those with the washers was a great idea. I went with the simple expensive path and just bought the direct replacement.

[Swath]

Most parts will clean up and should be usable. In theory you could look at re-release parts but a lot of them aren't compatible with the original cars. A repro body is available from Boki Racing https://www.bokiracing.com/product-page/boki-kyosho-ultima-body-wing and the stickers from MCI https://mciracing.ca/products/1-10th-kyosho-ultima-pro-decals.

Be aware a lot of old electronics just stop working from just being old, the materials break down and metals corrode, but if you plug them in and they run there's no problem using them. The crystals can be a pain, it is hard to find them these days and as they are delicate so easy to break.

The body in the link you sent is for an Ultima II, not sure how different they are. The Ultima Pro has a mini wing underneath the big wing, that is the only real difference I see.

The stickers link is great, those look very good, I will buy a set from them.

All electronics fired up nicely, everything seems to be working as it should. Of course that was just the electronics alone on the work bench. Heck, even one of the old batteries charged up and functioned for my smoke test.

[terry.sc]

The body in the link you sent is for an Ultima II, not sure how different they are. The Ultima Pro has a mini wing underneath the big wing, that is the only real difference I see.

It's the same body, the mini wing is moulded into the bottom of the rear panel of the body. The Ultima II just cuts the back off the body to clear the speed control resistor.

[Swath]

The body in the link you sent is for an Ultima II, not sure how different they are. The Ultima Pro has a mini wing underneath the big wing, that is the only real difference I see.

It's the same body, the mini wing is moulded into the bottom of the rear panel of the body. The Ultima II just cuts the back off the body to clear the speed control resistor.

Upon closer inspection of the pics I see that now, thanks!

[Swath]

I still have a few critical bits to get in via snail mail. But it is nearing completion. I still have to build the shocks, I just wanted to get a fitment done to verify I have all the parts needed. I still need springs, the rears may be ok but I don't have the short fronts, the ones on there are a set of rears I cut a couple loops out of just for a dry run of things. I have not found a single front tire in my batch of crap! Kind of weird, they got misplaced somewhere, perhaps I need to revisit my shed.

The star tool by itself is the one that came with my kit back in the day. Interesting they still make and include them. The vintage one has no markings, the newer ones identify the size of each end.

Tires from the period:

[juicedcoupe]

Why not a set of modern 2.2 tires and wheels?

These wheels are from the re-re Turbo Scorpion, and the tires are Schumacher. The rears are 12mm hex and the fronts are regular bearing mount.

20241209_012259.jpg (66.49 KiB) Viewed 177 times

20241209_012259.jpg (66.49 KiB) Viewed 177 times

[Swath]

Why not a set of modern 2.2 tires and wheels?

These wheels are from the re-re Turbo Scorpion, and the tires are Schumacher. The rears are 12mm hex and the fronts are regular bearing mount.

20241209_012259.jpg

I'll be running it on a clay indoor track initially so I will put some modern tires on it designed for that. For sitting on the shelf it needs some of the knobbies.

[Swath]

I was performing a break in of the ball diff and discovered a significant vibration. I also noticed a groove being worn into my rear turnbuckle rod ends from the wheels being to close.

I measured the offset of those white ones against another set and they definitely were set back further. I also noted the wheels and axles had a lot of in-out play in them, too much. I reread the manual to see if there was some spacer I had missed but nope. I put some shims in between the bearing and the hex and removed the play. It took .9mm on each side.

However, that was not the cause of the vibration. The vibration was definitely less with the wheels off but still there. Then I noticed it seems worse on the right hand side. I swapped the axles and the vibration moved to the other side. I surmised this to mean the axle was bad, new on order. (I also ordered some new hexs.) More waiting....

I did finish the break in and setup of the ball diff. It can more easily be done with the wheels off and axles pulled but I'm glad I attempted it the other way and found those issues.

Today I got a sticker set in the mail so I decorated the original body to resemble the picture on the manual.

Sticker pics below, notice my high tech blue tooth front wheels.

[Swath]

I finally found my front tires and wheels. I'm glad to have tracked them down. Specifically the yellow fronts which I believe to be the most original. The yellow and the chrome are identical aside from color. They are 2" wheels. The other wheels are 2.2", and the white one's offset isn't quite correct for this rig. All from back in the day. The rubber all seems to be in very good shape, no cracking at all. A few sets look like they were never used.

That yellow set was the only tires glued on, they came off fairly easily, I have just a little clean up to do.

Those tires are quite worn, I'm guessing that was my first set.

This white set still has bearings, I assume this was the set I was racing on when I put it all away in 1990.

[Swath]

Not quite ready for running on the track, I still need the axles and I have to finish up the shocks (they need a little luvin with some polish).

But it is looking the part: