Yokomo 870C aka.1988 YZ10 build with

White winter arms
2mm fine pitch drive train
Yokomo Hotlaps wheels
Lightened diff cups
Composite Craft shock towers
Front aluminum bulkhead
AE steel turnbuckles from RC10 Worlds re-release kit
SRS steering blocks

Hotdog4 built with
AE 870C shock towers
MX4 rear aluminum CVD bones
Academy molded wing
Extended wheelbase with longer rear belt
White Kydex bumper, homemade
870C shocks with later shock ends for Works arms
AE steel turnbuckles from RC10 Worlds re-release
Magnesium bulkheads

Hodog4 has the copper springs now

And, few more pics with C4 body

This post would be a help. but it seems impossible to get them unless you guys push MIP to make them again.

Yokomo YZ10, Works, and 870C universal drives info

it’s the basic info for Yokomo CVD bones
’94 YZ10 front CVD bone 84mm
’94 YZ10 rear CVD bone 79mm
MX4 rear CVD bone 79mm

Kysho RB5/RB6 70mm CVD bones work for 870C F/R

MX4 rear bone works with ’94 YZ10 rear. and, Works F/R
’94 YZ10 rear bone works with Works F/R. and, for 870C front wide setup
Bj4 front bone doesn’t work for Yokomo diff cups

’94 YZ10 front

from the top, MX4 Rear / ’94 YZ10 Rear / Jconcpets BJ4 front.

the length are identical to each other. but the head pins are not. I’ve tried more CVD bones from AE and Losi. and all the US brand CVD bones have bigger head pins which don’t fit Yokomo diff cups

While the length is identical, Bj4 CVD bone don’t work for Yokomo diff cups

’94 yz10 cvd bones go deep inside of the diff

MX4 bones have longer head pins. it’s fine except for 870C

I started this build on my personal blogspot blog. then I moved whole the articles on slowbean. I might want to arrange them into one single thread later.

it’s my yokomo Hotdog4 built from YR4 kit with some Works bits, along with Yokomo Esprit stock motor. I’m working on the new shock towers. 

MX4 rear CVD bones fits perfect for ’91 through ’93 Works. Hotdog4 has the same arms. and you guys can see the result. the length is same with post ’94 yz10 rear cvd bones.

[Updated]
Do not use the small black O-rings in the kit.
use metric O-rings which is hard type. not the soft ones like in AE shocks. the orange ones from later Yokomo shocks worked well.

Put black large cap seals. Yokomo ones are not helpful. AE shock cap O-rings works fine

Do not put the shock end till you finish the shock. you can adjust the rebound without the shock end

[Original Post]
The purple shocks look great and leak bad. and there are two different way to build these shocks.

The old way is with springs inside. and another method is with a thin washer instead of the spring. both hold the plastic bushing tight and prevent the leak. but the washer is more simple and works better to me. another problem with the spring method is the stroke keeps getting smaller while the oil leaks

It’s easy to exchange the spring to the washer. the later kit came with 10mm thin copper washer, and any thin washer with 9~10mm diameter works. but the inside hole should be 4mm or more. this margin makes the piston and the red large seal doing their jobs. and, don’t forget AE green slime

Sometimes we got broken shock shafts or alumium shock ends. or I want to use this non-leaking purple shock on my Hogdog4. later yokomo shock shafts are 3mm thick and they are too thin to be replaced. AE shock shafts work well with 870C shocks.

For this, you need to use the washer, not the spring. otherwise the shocks leak

With Composite Craft graphite shock towers and today’s work

#yokomo #yz10 #cvd #870c

The kingpins from 870C through YZ10 are basically same shoulder screws. even you can find the replacements from Tamiya and Kyosho as well. and MX4 kingpins are flanged bushing (flanged sleeve) which are easy to assemble and hard to be lost

The flanged sleeves should be assembled from inside to out on the front C hubs.

But, YZ10 C hub has a bit small room for MX4 kingpins. and both assembled from top to bottom. like these pics

All done with titanium screws, and ready to run.

Found some for myself and friends recently. I had a few while ago. but haven’t seen them for a while

There were 2 different ZD-304S from Yokomo. the early one is more simple, and later one came with idler bearings

the first one is here. it’s very unique with 4 of 4-40 SAE flathead screws on the bottom. they are the same screws you can find from AE cars. and I’m not sure with the later version. I haven’t opened the bag yet

And, this is the later one.

Someone posted some decent pictures of the 2nd version on Tamiya club.
http://www.tamiyaclub.com/showroom_model.asp?cid=121643&id=23290

There are two different versions
ZC-300AF Aluminum front bulkhead
ZC-300FC Aluminum front bulkhead for Works ’93

those two are basically same, except for the caster angle.
ZC-300FC for Works ’93 has bigger angle as you can see from the last picture
if the caster is same with the magnesium bulkhead, it’s 300AF. you can see that without the header.

Probably, I posted this somewhere. and I’m doing this again to remind my memory.

it’s the simple comparison

’94 / ’95 / ’97 YZ10 front > ’94~’97 YZ10 rear = Works ’91 / ’92 / ’93 Front = Works Rear = 870C front long version (with outer mount hole on the front arms) > 870C Front = 870C Rear

so, there are only 3 different lengths from Yokomo from ’87 through ’97.
but, there are more than one model number for the same length. it’s about the solidity.

870C universal drive, ZC-421 (front long version ZC-422) are softer than ZC-422A which is Works F/R universal drive. but ZC-422 and ZC-422A still have the same length.

there are ZC-423, ZC-423S, and ZD-423. all they are for ’94~’97 YZ10 front and the differences are solidity as well. it’s just about the material

Yokomo keeps testing and making new parts for their current and next models. it’s the reason they keep changing the model numbers and making newer ones. I respect that

From left to right,
ZD-423 = post ’94 YZ10 front, super hard version (same length with ZC-423, ZC423S)
ZD-422 = post ’94 YZ10 rear, super hard version (same with ZC-422A which is for Works)
ZC-422 = 870C front long version (same with ZD-422, and ZC-422A)
ZC-421 = 870C F/R

the actual length from the end to the other end is
107mm, 101mm, and 96mm
the length from the end to the universal joint is 25mm

my ’94 yz10 runner got a new shell with some decals today.

now it runs with
HD universal drives
Yokomo Aluminum motor mount
Team Suzuki F/R hubs and hub carriers
’93 WCS steering

[update from July 2nd, 2015]

found the MX4 wheel hubs for YZ10. and more MX4 wheels for this setup too.

pargu is working on the wheel hubs. you guys can use them pretty soon.

these 2 threads from rc10talk.com got lots of pics and information. i started this project from those as well
http://www.rc10talk.com/viewtopic.php?f=29&t=17274
http://www.rc10talk.com/viewtopic.php?f=29&t=15520
also this thread got lots of detailed pics
http://www.rc10talk.com/viewtopic.php?f=29&t=26696

my goal is building a ’93 WCS YZ10 replica with newer electronics and tiers for vintage race. i still need to get some correct parts for a replica. and, now i can run this before i get them. it’s a runner before a replica

I made this list from Asso_man!’s RC10talk thread a couple of years ago. and just noticed the file I uploaded has gone somwhere.

Yokomo YZ10 W.C.S part list thread on RC10talk

the scanned images are here

Yokomo YZ10 Pavidis Part list #1 & #2

Matt reminds me that I put these buttons and mounts on my yoke runners. the purple mounts on my MX-4 and ’94 YZ10 came from Trinity. also the gold wing buttons are my favorite. only have 2 sets of each buttons and mounts. and want to find more. only the problem is.. I cannot remember which company made the buttons. haha

I bought this MX-4 at the first day it came from the factory. I remember it was April maybe May ’98. and it’s still one of my favorites. actually I was faster with Losi XX4. but mostly raced with this MX-4. and I could learn more about race and setup from this beauty. everything is still fine except for the rear tires on the front wheel.

this trick is great for protecting the spur. the first batch came without this foam in the boxes. and they started to put this in the kits a couple of months later from the release

it came at ’95 with Works 91/93 arms on early YR-4 chassis. it was out of my concern ’cause I already had all of Yoke buggies except for 834B. and it looked funny at first glance and seemed to be packed from the leftover parts of YR-4, Works, and YZ10. but this kit has a few good parts for building or restoring Yoke buggies.

like:
the wing is the same one on 870C and Works
rear axles are perfect replacements for 834B
the body is almost identical to Protech 4 which was stock ’88 YZ10
Works arms
YZ10 wheels and Pavidis tires
it came from Yokomo

dislike
only 6 diff balls for each diff (50%)
sedan shocks and towers (.56 stroke)
have to replace the center shaft if you want to install TCS or torque limiter
funny bumper
molded F/R bulkhead (it could be good from a different point of view)
early weak hinge pins which are too long
funny box art

anyway, I found a NIB lat week, again

and few more pictures from the kit I split for my 870C build a couple of years ago

won the 1st at 4WD, and 2nd at 2WD. I still have 3 more races remaining this year. and the start was not bad. the motor was limited to 540 till last year to protect fragile tamiya buggies. the rule have changed on the motor. and it’s 23T (=13.5T) now. and they made the “insect class” for grasshopper and it’s friends. it was a great fun to watch insect class race. I rent my grasshopper to my friend. and he got the 3rd on the class

RPM ’91 conversion on FL tub. it’s one of my favorite buggies.  the track is narrow. so I put this reversible ESC for 2WD class. the steering came from my ’94 worlds which got MIP steering after I took the original steering off

Tires: front Jconcepts rib
rear Proline bowtie
Motor: Yokomo M stock 23T
ESC: Novak Rooster 12T

’94 YZ10 with a few mods. the winter is very cold here. and the yellow and soft 834B steering worked great. my favorite setup with yokomo buggies is 5/64″ thrust balls like AE cars. larger 6 (or 7) balls can make smooth and durable rear diff than tiny 8 of 1/16″ thrust balls in the kits can do

Tires: front Losi Blockhead
rear Losi Bar Codes
Motor: Speed Passion V3 13.5T
ESC: LRP Sphere comp. 2007 edition

maybe it’s the best trick for the race.
hot pack rules!

Stock epoxy towers were strong enough. but later world champ edition towers are not. I’ll try FL towers at this weekend. thanks to my friend uncle grampa Al

https://slowbean.net/2010/12/yokomo-yz-10-runner/

I went back to older ’94 chassis from ’95 Worlds Spec (Pavidis edition). ’cause the original chassis looked better for Lipo setup. and it is

’95 chassis is still great for looking and was for running. but   we don’t need the weight saving holes anymore with Lipo setup. even the chassis is not strong enough for Lipo + brushless

older epoxy topdeck always worked for me. so, I went back to it

YZ-10 with Lipo seup