Kyosho MP9 TKI4 Build

Kyosho recently released the new TKI4 buggy, which is the newest iteration of their championship-winning MP9 platform. I decided to do an in-depth build article, including building tips, and suggestions on how to get the most out of the build experience.


Kyosho organizes all of the parts bags numerically, corresponding to the build steps in the manual. All parts are easy to find.


Differential Assembly

When building a new kit, I like to lay out all the parts for each step, before assembly. This takes more time initially, but allows me to check that there are no missing parts, and makes assembly easier. The diffs in the TKI4 are the same spec as those in the TKI3, still with a larger diameter center diff, for more fluid capacity and less heat build up. The outdrives are lightened and hardened for durability.


Included in the box is a small tub of Kyosho white grease, but I prefer to use red Mobil 1 synthetic grease for the outdrives and the o-rings. Make sure to coat the groove in the outdrive fully with grease before assembly.


Diffs assembled and ready for oil:


The front and rear differentials are smaller than the center diff to save weight, so a set screw is required to remove and install the cross-pin. When I install the set screw before filling the diff with oil, I like to use a drop of CA glue to ensure my diff will not leak. Make sure the set screw is flush with the diff case, otherwise it will contact the pinion gear, causing binding in the drive train.



The instructions tell you to install the diff into the gear box (Step 3) before installing the driveshaft (Step 4), but to make setting the spacing on the pinion gear easier, I like to install the center driveshaft before installing the diff into the gear box. I set the spacing between the gearbox and center driveshaft (See diagram C in Step 4) first. Then I install the diff into the gearbox.


Rear Shock Tower, Gear Box, Suspension Mount and Driveshaft


Rear end assembly coming together:


Completing the Rear End


The kit includes revised rear hubs, which utilize updated eccentric delrin bushings to allow further adjustment of the roll center:


When assembling the rear hubs, I like to install the outer bearing first. To install the inner bearing, I slide it onto the universal axle, then push the axle into the hub. This seats the inner bearing in the hub uniformly and quickly.


The completed rear end assembly:


The completed rear end assembly attached to the chassis:


Front End Assembly


As with the rear hubs mentioned earlier, I assemble the front steering knuckles the same way. I install the outer bearing first. To install the inner bearing, I slide it onto the universal axle, then push the axle into the steering knuckle to seat the bearing. The kit includes slightly shorter steering knuckles and longer steering links, for a reduced ackerman angle. This translates to smoother steering and higher corner speeds on the track.


Make sure to clean the threads on all screws that go into metal, to remove residue. Once clean, apply a drop of thread lock. Applying thread lock to a screw that has not been cleaned will not allow the thread lock to work properly:


The kit includes long set screws for the lower front swaybar mounts. This makes for a cleaner installation, and more clearance compared to using a button head screw:


Completed front end assembly:


Front and rear assemblies attached to chassis:


Brakes and front steering assembly:


Radio tray and fuel tank assemblies:


I use the KO Propo Electrical Switch 2, which fits nicely on the transponder mount in the radio tray. To mount the switch, trimming of the rear box is required, as shown:


Trimmed radio box:


KO Propo Electrical Switch 2 installed:


Completed radio tray:


Radio tray, center diff and steering assembly installed:


Engine mount and clutch assembly. Included in the kit is a 13-tooth vented clutch bell, for better heat dissipation. Also included are a set of 7075 aluminum clutch shoes and 1.0mm springs:


Shock assembly: Make sure to use O-ring lubricant, such as O-Slip, Green Slime, etc. Also make sure to bleed the shocks before installing the shock boots. This will help with bleeding the shocks more accurately. I like to build my shocks with zero rebound. The preload collars on the shocks are black anodized and etched, for easy ride height adjustments. I will be doing an in-depth shock build article soon.


Finished build. The kit includes an updated wing with center air dams and two different sized wicker bills:


The build went together very smoothly, and the fit, finish and parts quality are all amazing. I want to thank Kyosho for making such a remarkable car. A special thanks goes out to Yuichi Kanai, Joe Pillars and Derek Furutani.

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