Cat XLS Masami 4WD New Build With All The Upgrades Available. Part 1 (New Parts).


 Cat XLS Masami 4WD New Build With All The Upgrades Available. 

Part 1.

If you have not read the following posts, please follow the links below:-


New Parts


Hello fellow RC enthusiasts from around the world, I hope you are all well.

Before we start, this post is going to be very long and will continue to grow. As you may imagine there are many hundreds of components needed to complete this mammoth task. It will also cost a small fortune to fund this project. Therefor, I urge you to think carefully before attempting such a difficult, tedious and very, very costly task. 

Let us begin,

In this post I will be building a Cat XLS Masami from scratch. These parts have been sourced and purchased individually according to part number from the original build manual. However, to keep delivery costs down, I did buy many parts in bulk and from the same supplier. Otherwise it would been an even more expensive exercise. These upgrade parts were intended for my Schumacher Cat XLS pictured below. However, I did not have the heart to disassemble my beautiful buggy. Instead, I decided to build a new Cat XLS Masami from the upgrade parts I had. Then I sourced and purchased the other parts I need/needed, directly from Schumacher UK. 99% of the parts I am using are Genuine Schumacher components. Only two other component manufactures will be used,

1) Muzzoom Models for the steering upgrade.
2) Tamiya for PS paint.

I have purchased almost all the parts from the links below;

All of the above are brilliant suppliers of original and some have innovative race options that few know of. I give them all an absolute 10/10 and are my go to RC car companies, without doubt. May I add, I am not sponsored by any of the above companies. I wish I was.

The list of parts (from the original Schumacher Cat XLS Manual) I (we) need is immense and some parts need to be duplicated in purchase due to the amount needed of that particular component. I have added how many packs of each component that is needed however, this list may change as the parts are sorted into their build stage. Schumacher do not supply a bill of materials, but this is what I need.
  See below....


The chassis parts only require 1 part of each. I have marked each section with either a pack or individual parts, especially for nuts, bolts, screws and washers. For example U7229 requires 37 of that particular screw.
As you are aware I am using the carbon fibre parts but the above list is for a standard Cat XLS Masami, if you decide to follow this torturous project.

My parts pictures are not the best, as they are still in their original bags. As soon as I need them or use them I will show the parts in better detail.

I will also give you the price I paid for every part.

Believe me there are hundreds of parts to buy and describe, so I will push on with their descriptions and prices .

Above is the U7236 Pro Transmission Upgrade.

 Yes it is very expensive, but you get a lot for your money with a "full new transmission kit". With the XLS now discontinued, I had to have one for my Cat XLS Masami.  Also, please notice the price. If you buy each piece separate, it will cost approximately £170.13. Whereas the full kit version is approximately £95.00. I understand it's not the sale of the century, but £75 is better in my pocket than in anyone else's. 

The picture above shows 3 new body parts:-

U5136 - Upper Body £17.09, which is supplied with window masks, some decals and IS covered with protective film.
U5137 - Lower Body £9.49, which is NOT covered with protective film.
U5138 - Rear wing £5.70, which IS covered with protective film.

All of the carbon fibre parts below were bought from Modelsport.

The picture above is the carbon fibre chassis U7263 £44.09. I must say this chassis is a lot more rigid than the original. I would like to know the weight of each chassis however, I cannot weigh the original as it is fitted to the car. The normal rule of thumb is more rigidity, results in better racing lines on the circuit.

Above is the U7265 rear shock mount £7.83. This is a really thick, heavy duty mount. Again, a lot thicker than the original. 

Above:- U7266 rear suspension support £7.83. The pictures do not show how beautiful or how thick these carbon fibre parts are in real life. As I stated earlier, when I come to use them I will show a more detailed picture of each item.

Above:- U7267 LiPo straps £9.79. 

Above:- U7268 servo spacer and C.T.R. £5.87. All those carbon fibre parts should stiffen up the chassis for a much improved racing chassis and faster racing lines in races. The U7268 is actually only one half of the steering upgrade with an upgraded ball raced steering being the other half.

The long item at the top is the U5139, which is a new belt cover and I paid £9.39. I had forgotten how thick the Schumacher polycarbonate plastic parts are. The under body and belt cover are required early in the build. These parts will need cutting and shaping before the build starts.

At the right of the above picture is U7245, which is a pair of alloy eccentric belt bearing tensioners. On the original (K172 Kit) XLS they are supplied as a plastic pieces. The new alloy upgrade parts are quite expensive for what they are. However £19.50 is small price to beef up the original plastic ones as they hold the belt's shaft tensioner bearings.  When I was looking at pictures of these online, they looked silver but are in fact anodised black with the machining in silver with superb machine detailing. They will look so cool against the silver motor and cover plate.

The next three parts I have purchased were, in my opinion were very expensive. However, I had to invest in them as these parts are quickly becoming difficult to find with prices rising daily it seems. 

U7293 Alloy Front Transmission Housings. These were the most expensive of the three new upgrades. It cost £31.35 and worryingly comes with a drill bit and some screws. I bought all the alloy upgrade parts from Modelsport too. Unlike the original plastic parts, the alloy parts are pre threaded and supplied with engineering screws. I must remember to be careful inserting the engineering screws as I do not wish to strip the threads on this expensive part. However, I have invested in a drill and tap set in the case of such an event.


 U7292 Alloy Rear Transmission Housing Inner and again, this came with a drill bit.

The picture above shows the drill bit in the Rear Trans Housing Inner piece. It is also supplied with engineering fixing screws as some of the holes are pre threaded. This part was £24.49. 

Below U7294

U7294 Alloy Rear Transmission Spacer. This parts also comes with a drill bit and engineering screws. This was the cheapest of the three parts costing £19.59. This part will sit right at the back of the buggy. As the picture shows the part sporting the Cat XLS motif and the Schumacher name at the top. It should look very cool with the carbon fibre parts.

Another picture of U7294, showing the engineering screws. Again, as with all the alloy parts I will have to be careful inserting all of the bolts as I do not want to strip any threads on these expensive parts.

Above is a picture of the not well known plastic rear wing mount that replaces the ugly yet useful wire holder from the original kit. The part number is U3850 and cost £7.95 from Ebay. This should once again look cool with the other upgrades. This part is a suggested upgrade on the rear inner page of the instruction manual and is classed as an off road rear wing bracket.

Above is a picture of a highly recommended ball raced steering upgrade that is needed for the carbon fibre steering (U7268) upgrade. So its a double upgrade. It was £28.50 and the part number is MUZ- 170601b. It was from Muzzoom Models and came with some stickers, which is a bonus! I can remember that the XLS already has a highly impressive and quick steering control, so with this upgrade it will be lightning fast.

All of the many, many parts below were bought from Schumacher RC Racing

Above is a picture of the further parts I will need. These parts come as standard in the K172 Kit and are as follows:-

U7141 cover plate £7.99.
U7192 servo mount mouldings £2.99.
U1042 aerial mount £2.99.
U7140 motor plate £7.99.
U7188 bearing housing £4.99.
U7219 M3 x 8 pan head pozi £1.99.
U7221 M3 x 12 pan head pozi £1.99.
U7226 No2 x 3/16 pan head £1.99.
U7229 No4 x 3/8 pan head £1.99.

I can hear your thoughts about the original Schumacher screws, bolts, nuts, washers and the cost of the each item. This is simply because I want a "REAL" Schumacher Cat XLS Masami, and not cobbled together out of second hand junk and spare parts. I have seen such cars, made from said "spares" and they want hundreds of £'s for them. 


An easy way to detect such buggies is by checking the screws used in the manual. These cheap £11.99 screw sets are a waste of time and money, believe me. They are not bespoke for this car or any other to be fair. With this car in particular we have 26 different screw types alone, as needed for the build. The screw/bolt and description of said item will be in the manual and designed for its intended use.

The above original Schumacher items are:-

U3495 Ball studs £2.99.
U7152 UJ assembly x4 £15.96.
U7155 Bearing 8 x 16 x 5 (Black Seal) £3.99.

The Above parts are mostly for the front and rear shocks, which were quite expensive but the quality of the complete assembly is fantastic. When complete the shocks have a very smooth operation. These parts are:-

U7145 Rear shock bodies (pr) £9.99.
U7146 Front shock bodies (pr) £9.99.
U729 Chrome steel balls 3mm (pk 36) (not needed with U7236 Pro Transmission kit) £3.99.
U7148 Rear shock shaft (pr) £3.99.
U7149 Front shock shaft (pr) £3.99.
U7143 Differential shaft (pr) £2.99.

The above parts are all original speed pack parts, which means they are types of screws and e-clips etc. Again these are all standard parts supplied in Kit 172.
These parts are:-

U7151 Steering posts £2.99.
U1960 "O" rings £1.99.
U1633 Small pins £1.99.
U7224 M3 x 40 csk pozi £1.99.
U7227 No2 x 1/2 Pan hd £1.99.
U7228 No4 x 1/4 Pan hd £1.99.
U1547 M3 nuts £1.99.
U1548 M3 washers £1.99.
U1551 E clips £1.99.

Above we have mainly plastic parts, of which are again all standard parts supplied in the K172 Kit. These parts are:-

U4968 Ball sockets £2.99.
U7185 Front upper wishbone pivot £1.99.
U7144 Drive shaft mouldings £9.99.
U7208 Front bumper £6.99.
U7190 Steering lever mouldings £4.99.
U7191 Trans spacer mouldings £3.99.
U7194 Front suspension brackets £4.99.

I do apologise for speeding through the parts, but there are still quite a few items to describe. I suggest we push on.

The parts pictured above are as follows:-

U7180 Lower wishbones (x2 packs/4 in total) £13.98.
U7179 Upper wishbones (x2 packs/4 in total) £13.98.
U7195 Front pivot bracket £7.99.
U7200 Rear hub carrier (pr) £6.99.
U7199 Front hub carrier (pr) £6.99.

  With the above parts being:-

U7196 Upper & lower front wishbone spacers (x2) £3.98.
U7186 Rear suspension brackets £4.99.
U7217 Crash back "O" rings £1.99.
U7169 Suspension spacer (x2) £3.98.
U7201 Rear pivot blocks £4.99.
U7207 Anti roll bar clamp £3.99.
U7209 Ball sockets £2.99.

 The mostly metal parts above are:-

U7160 Upper pivot pin £1.99.
U7162 Lower pivot pin rear £1.99.
U7159 Crash back pin  (x2) £3.98.
U7161 Lower pivot pin front £1.99.
U7167 Front anti roll bar £2.99.

And moving swiftly forward with the above parts, which are:-

U4299 Turnbuckle HT 52mm £2.99.
U7163 55mm threaded stud £1.99.
U4222 Turnbuckle adjuster HTT-39mm £2.99.
U4221 Turnbuckle adjuster HTT-24mm £2.99.
U7170 Shock top bush £2.99.
U7262 Anti roll bar ball £2.99.
U7150 Pivot ball £2.99.

In the above packs are all different types of screw needed for the build, and include:-

U1547 M3 nuts £1.99.
U1548 M3 washers £1.99.
U3131 Alloy spacers £5.99.
U7164 M3 x 12 £1.99.
U7165 M3 x 16 £1.99.
U7220 M3 x 10 (x2) £3.98.
U7222 M2 nut (x2) £3.98.
U7223 M3 x 12 grub £1.99.
U7225 M2 steel washer £1.99.
U7226 No2 x 3/16  (x2) £3.98.
U7227 No2 x 1/2 (x2) £3.98.
U7229 No4 x 3/8 (x3) £5.97.
U7230 No4 x 1/2 £1.99.
U7231 No4 x 3/4 £1.99.
U7232 No4 x 1 £1.99.
U7258 M2 x 16 £1.99.
U7259 M3 x 8 £1.99.
U7260 Disc spring £1.99
U7275 M3 x 8 £1.99

Once again I apologise for thundering through the parts but I remind you this is a massive and time consuming task.

The four parts bags above contain the following items:-

U7273 Rear shock springs (2) £2.99. There are other springs available with different ratings and colours. I went with the iconic chrome ones that come in Kit 172.
U7272 Front shock springs (2) £2.99. Again there are a variety of colours and rating available.
U7147 Shock body screw on cap (2) (x2) £19.98. Yes they were quite expensive, however I can speak from experience, the complete shock assemblies are super smooth and don't leak.

Above we have:-

U7171 Shock bushing (2) (x2) £6.45

The two parts above are:-

 U7172 Shock rebuild kits and cost £5.68 for both. I decided to buy the rebuild kits as buying all the parts separate would have cost more for postage alone. Another positive for this method is less separate bags and they are all in one place. As you can imagine, the amount of parts I have collected is massive. 

The above parts are as follows:-

U7150 Pivot ball (pk4) x4 and cost £11.96.
U7261 Shock mouldings (pk2) x2 £11.98.
U7218 M3 x 6 Bolt £1.99.
U7210 Shock sockets (pk4) x 2 £5.98.
U7155 8x 16x 5 bearing (pk2) x4 £15.96.
U7209 Ball sockets (pk4) x4 £11.96.

Above is a picture of U7264 C/F top deck and I have been waiting for this part for 8 weeks. It cost £24.00 and is super rigid. It should be an excellent overall chassis and looks beautiful.

Above is a picture of the extremely rare rear anti-roll bar kit. Again, I have been waiting about 8 weeks to find this part and it cost me £11.50.

 There is always something you forget to buy and this was my item. It is U7166 M3 x 20 bolt and cost £1.99 for a bag of 10. There are only 4 used in the whole kit but when I was putting the bags together I noticed they were missing. I have also purchased a full set of JC Racing five spoke wheels in black, and were £9.50.

I love these wheels and they are quickly becoming harder to find every day.


To finish the list of components and complete the K172 kit is the rear outer trans housing above. The part was £4.79 and bought from Make It Build It. 

I almost forgot to add the tyres I will be using. As the JCRacing five spoke wheels are 2.2" in diameter, my tyre choice is almost endless. I decided on Schumacher full spike front Slim and wide rear. The parts numbers are U6595 for the front and U6596 for the rear. They are coded yellow (soft) and were £15.20 for the 4 from Make It Build It!! The reason I like them is they are almost identical to the tyres supplied in the kit and should suit the completed buggy.

 I am allocating each part to the build sequence, in separate bags as they are required in the official Schumacher build manual. See the picture above. Each bag is numbered, sequenced and labelled. In Part 2, I will be detailing each sequence bag, it's contents for each and every component within that stage/sequence number.

Now this post is complete, it will no longer be updated unless I find any errors or recommendations from readers or from investigation. 

Thank you for reading. I hope you have all enjoyed this post. I also hope it can help all Schumacher Cat XLS Masami owners achieve a better understanding of their glorious World Champion Winning buggies.

Follow the link below to look at this stunning example from GCMRacing.

Until the my next post, take care my friends from around the world.

CATXLS 08/05/2021

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Unknown said…
Wow Baz that is some immense research ordering and pile of parts haha the hard work will result im an amazing buggy mate.
Catxls said…
I hope so Pete! It also cost a small pile of cash, many grey hairs and lots of paper during the research. Thanks for reading and commenting bud. I know you are just as passionate as me with all that is RC!! Thumbs up!!