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
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.
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.
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
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
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