Yokomo YZ-4 SF
#16
Tech Adept
Joined: Jun 2017
Posts: 209
From: Geelong
So I finally finished my kit and I'm now waiting on my motor, ESC, servo, and reciever. I decided to take pics of every step and put down some thoughts that I had along the way. If anyone has any questions or wants some more pics let me know. Here we go!
Here's the gallery of pics. Not the best, but I hope they help.
Step 1-2. Pic1-Pic4
I had a bit of excess flashing on my side plates. Nothing major. Just trim it if you have the same.
Make sure you assemble your battery post before screwing the side plates on. An even better idea is to work out what betteries you will be using and build the posts to suit. Jump ahead in the manual to one of the last steps if you're using the low profile shorties and it will tell you to omitt the spacers and use different screws. The manual says the screws are not included but at the end of my build I had some spares.
Step 3. Pic5
I've noticed in the manual it doesn't say to use any threadlock when screwing directly in to the aluminium parts. I followed the manual but I did threadlock the upper arms mounts to the bulk head as I have heard that they come loose.
Step 4. Pic6
I had a problem with one of the screws in the diff case. It didn't seem to lock down like the rest of them did. I will see how it goes. Both ring gears seem to be the same size and tooth count. I know the 22-4 2.0 uses a different gear on the front than what the rear is. There was also a bag of shims in the bigger bag that are not used at all in the build.
Step 5-8. Pic 7
Take note of how many shims are used on each side of the diff, and what order they go in. I've read that some people have needed to use extra shims.
Step 9-11. Pic 8
Work out what spur you will be using and install it in these steps. The kit comes with an 87t but I ordered an 84t for use with the 13.5 motor.
I've noticed the spurs don't actually have any markings on them which makes it hard to identify.
Make sure you clean the main shaft and the drive cups well. Apparently some poeple have experienced the set screws coming lose.
I quite like the slipper design on this car too. The manual suggests to tighten the nut all the way down to break the spring in. Not sure if compressing it with pliers will do the same thing.
Step 12. Pic 9
Make sure you use the correct shims and washer for the steering. Shims go on top the center link, and the washers go beneath.
The steering is so smooth and has no play at all. I'm going to upgrade to the aluminium bell cranks though.
I didn't use the body mount. I'll see how the body goes once I've got it ready, but it should be fine with the velcro.
Step 13-14.
Be careful of how you install the shock tower spacers. The lips should go towards the outside of the buggy.
Again, I omitted the body mount but I still used the screw in the wiung mount.
Step 15. Pic 10 - Pic 13
This is where the manual goes a bit strange. There are some shims included with these bags that aren't used to for a couple of steps ahead.
I felt like my front arms could have done with some shims or a spacer on the back. You can see in the pics that there's a bit of room for movement on the hinge pin. The rear arms have no play at all because of the spacers.
I used 15 degree alumium front hub carriers. I also have 8 degree aluminium on the way. The kit ones are 8 degree in plastic. I will see what works better at my track.
Step 16.
The wheel nuts on the back are different from the front. I would have liked the same ones on the back. If you look at Ryan Maifield's car from China he used the front ones on the back.
Note the spacers on the rear hubs. Much better than the front.
Step 17-18.
All went okay here. The tables for the toe in and antisquat can be a little confusing though.
Step 19. Pic 14 - Pic 15
I'm setting my buggy up for dirt so I used the dirt sway bars. The front seems a little thin. I ran into a problem with the rear sway bar. The manual says the bar should be 32mm on each side but that seemed to rub on the rear shocks. I've moved it forward a little and it seems fine now.
Step 20. Pic 16 - Pic 17
These turnbuckles are so easy and smooth to put together. I used some black grease on mine as I do with all my turnbuckles. I also make sure all the threads are going in the same direction.
There's cup end tool that fits onto your 7.0mm driver which makes life easier. Yokomo included a few extra cup ends. Not sure what they're for though. They are a bit smaller.
Step 21-23. Pic 18 - Pic 20
I wasn't too impressed with this part of the build. The shock pistons aren't marked so you have no idea what size holes they have, and there's nothing in the manual either. There were a heap of spares that also weren't marked.
I just had a look on the parts list on the website and the fronts (black) are 1.6x2, and the rears (white) are 1.7x2.
I wasn't too impressed with the plastic shock caps. I think for the money it should have come with the aluminiun caps. The bleeder screw doesn't seem like a great seal too. I will definitely be upgrading these. While I'm at it I may as well grab the titanium coated shock shafts.
I might have to change the springs, but I'll see how they go. Does anyone know what the spring rates are for these?
Step 24. Pic 21
The kit comes with a 19t pinion. I'll be using 25 ~ 27. I threw an old motor in just to see how it fit and it was quite nice. The mesh was very easy to set.
Step 26. Pic 22
Not much to show here as I don't have my ESC or reciever. There doesn't seem to be whole lot of room though. I'm a bit worried about running the wire to the reciever under the drive shaft though, hopefully it won't get caught or wear away. The servo mount is a bit odd. On side is aluminium and the other little piece is plastic. The small side floats and isn't secured to anything. The kit provides only enough screws and washers to secure the servo in three places as per the manual. I can't understand why the fourth spot isn't secured.
Step 27. Pic 23 - Pic 24
This step should have been at the start.
Here's where it tells you how to change the battery posts to use thinner batteries. It says the screws are extra but I had some spares in my kit. I hope no one has to buy 2 extra screws, as the kit should really come with them. I had to trim the battery foam too. The battery strap fits snug which is good.
So yeah, that's pretty much the build. I'm fairly happy with it and can't wait to hit the track next week when my electronics arrive. The quality was top notch and everything goes together so well. I almost opted for the B6D but I'm glad I went for the Yokomo. The upgrades I would have had to do to the B6D would have made it more expensive than this buggy. I'm even considering getting the YZ-2!
Here's the gallery of pics. Not the best, but I hope they help.
Step 1-2. Pic1-Pic4
I had a bit of excess flashing on my side plates. Nothing major. Just trim it if you have the same.
Make sure you assemble your battery post before screwing the side plates on. An even better idea is to work out what betteries you will be using and build the posts to suit. Jump ahead in the manual to one of the last steps if you're using the low profile shorties and it will tell you to omitt the spacers and use different screws. The manual says the screws are not included but at the end of my build I had some spares.
Step 3. Pic5
I've noticed in the manual it doesn't say to use any threadlock when screwing directly in to the aluminium parts. I followed the manual but I did threadlock the upper arms mounts to the bulk head as I have heard that they come loose.
Step 4. Pic6
I had a problem with one of the screws in the diff case. It didn't seem to lock down like the rest of them did. I will see how it goes. Both ring gears seem to be the same size and tooth count. I know the 22-4 2.0 uses a different gear on the front than what the rear is. There was also a bag of shims in the bigger bag that are not used at all in the build.
Step 5-8. Pic 7
Take note of how many shims are used on each side of the diff, and what order they go in. I've read that some people have needed to use extra shims.
Step 9-11. Pic 8
Work out what spur you will be using and install it in these steps. The kit comes with an 87t but I ordered an 84t for use with the 13.5 motor.
I've noticed the spurs don't actually have any markings on them which makes it hard to identify.
Make sure you clean the main shaft and the drive cups well. Apparently some poeple have experienced the set screws coming lose.
I quite like the slipper design on this car too. The manual suggests to tighten the nut all the way down to break the spring in. Not sure if compressing it with pliers will do the same thing.
Step 12. Pic 9
Make sure you use the correct shims and washer for the steering. Shims go on top the center link, and the washers go beneath.
The steering is so smooth and has no play at all. I'm going to upgrade to the aluminium bell cranks though.
I didn't use the body mount. I'll see how the body goes once I've got it ready, but it should be fine with the velcro.
Step 13-14.
Be careful of how you install the shock tower spacers. The lips should go towards the outside of the buggy.
Again, I omitted the body mount but I still used the screw in the wiung mount.
Step 15. Pic 10 - Pic 13
This is where the manual goes a bit strange. There are some shims included with these bags that aren't used to for a couple of steps ahead.
I felt like my front arms could have done with some shims or a spacer on the back. You can see in the pics that there's a bit of room for movement on the hinge pin. The rear arms have no play at all because of the spacers.
I used 15 degree alumium front hub carriers. I also have 8 degree aluminium on the way. The kit ones are 8 degree in plastic. I will see what works better at my track.
Step 16.
The wheel nuts on the back are different from the front. I would have liked the same ones on the back. If you look at Ryan Maifield's car from China he used the front ones on the back.
Note the spacers on the rear hubs. Much better than the front.
Step 17-18.
All went okay here. The tables for the toe in and antisquat can be a little confusing though.
Step 19. Pic 14 - Pic 15
I'm setting my buggy up for dirt so I used the dirt sway bars. The front seems a little thin. I ran into a problem with the rear sway bar. The manual says the bar should be 32mm on each side but that seemed to rub on the rear shocks. I've moved it forward a little and it seems fine now.
Step 20. Pic 16 - Pic 17
These turnbuckles are so easy and smooth to put together. I used some black grease on mine as I do with all my turnbuckles. I also make sure all the threads are going in the same direction.
There's cup end tool that fits onto your 7.0mm driver which makes life easier. Yokomo included a few extra cup ends. Not sure what they're for though. They are a bit smaller.
Step 21-23. Pic 18 - Pic 20
I wasn't too impressed with this part of the build. The shock pistons aren't marked so you have no idea what size holes they have, and there's nothing in the manual either. There were a heap of spares that also weren't marked.
I just had a look on the parts list on the website and the fronts (black) are 1.6x2, and the rears (white) are 1.7x2.
I wasn't too impressed with the plastic shock caps. I think for the money it should have come with the aluminiun caps. The bleeder screw doesn't seem like a great seal too. I will definitely be upgrading these. While I'm at it I may as well grab the titanium coated shock shafts.
I might have to change the springs, but I'll see how they go. Does anyone know what the spring rates are for these?
Step 24. Pic 21
The kit comes with a 19t pinion. I'll be using 25 ~ 27. I threw an old motor in just to see how it fit and it was quite nice. The mesh was very easy to set.
Step 26. Pic 22
Not much to show here as I don't have my ESC or reciever. There doesn't seem to be whole lot of room though. I'm a bit worried about running the wire to the reciever under the drive shaft though, hopefully it won't get caught or wear away. The servo mount is a bit odd. On side is aluminium and the other little piece is plastic. The small side floats and isn't secured to anything. The kit provides only enough screws and washers to secure the servo in three places as per the manual. I can't understand why the fourth spot isn't secured.
Step 27. Pic 23 - Pic 24
This step should have been at the start.
Here's where it tells you how to change the battery posts to use thinner batteries. It says the screws are extra but I had some spares in my kit. I hope no one has to buy 2 extra screws, as the kit should really come with them. I had to trim the battery foam too. The battery strap fits snug which is good.
So yeah, that's pretty much the build. I'm fairly happy with it and can't wait to hit the track next week when my electronics arrive. The quality was top notch and everything goes together so well. I almost opted for the B6D but I'm glad I went for the Yokomo. The upgrades I would have had to do to the B6D would have made it more expensive than this buggy. I'm even considering getting the YZ-2!
#17
Thank you boss
#18
Joined: Aug 2010
Posts: 4,610
From: Vancouver, Washington
On your step 15: I do not have excessive play using the stock plastic 8 degree hubs. Everything is nice and tight up there.Not sure, but maybe the Bmax/YZ-4 (Classic? hehe) blocks aren't supposed to be used on this car? and revised blocks are on the way for those wanting to use aluminum?
#19
Tech Adept
Joined: Jun 2017
Posts: 209
From: Geelong
On your step 15: I do not have excessive play using the stock plastic 8 degree hubs. Everything is nice and tight up there.Not sure, but maybe the Bmax/YZ-4 (Classic? hehe) blocks aren't supposed to be used on this car? and revised blocks are on the way for those wanting to use aluminum?
#21
Joined: Aug 2010
Posts: 4,610
From: Vancouver, Washington
I see that as well. Just know there isnt supposed to be that much play there. You'll have to order another set of kingpins to get those spacers. They are not sold by themselves.
#25
#28
Tech Adept
Joined: Jun 2017
Posts: 209
From: Geelong





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