To be honest I have replace at 1/4 of the screws and washers when building the kit for more appropriate sizes. Lucky I bought a Tony's screw kit when I built it.
The one that sticks out in my mind similar to your problem was the one piece engine mount. When you use the 12mm mushroom screws supplied with the XT8 the screws sit out of the top of the engine mount by 0.5 to 1.0 mm. This held up the mounts connected to the engine. I had to place a nut on the end and grind them down so I didn't have a rough thread which would strip out the engine mount. I now run the XB8 washer cups with 10mm screws.
You wold think the X ray race mechanics would let them know what does and doesn't fit. While I was building I kept thinking great quality parts but obviously the R & D department don't race or put a lot of these together.
Other changes were as follows;
- Rear wing brace screws removed and used in the front body mounts so I could place a nut on the end.
- 30mm screws used on rear wing mount screwed through the tower with a nut placed on the end at the rear of the tower/bulkhead.
- 3 X 16 mm stainless steel washer used to replace plastic washes to attach the wing
- 30 mm screws used on all suspension lower rod ends. Drilled out arm to put a nut on the end so screws would not back out.
- 12mm screws used in the radio box after they were all stripped. Strong throttle/brake servo. I used 10mm screws were the screws for the servo intersect.
- used3 X 6mm washers on all pivot pins to cover the pins more
- Changed screw sizes for both aluminum braces (Can't remember what sizes)
- Changed shims for the clutch used the NTI shims 6X7 X 0.2 t 0.5mm so the shims would only touch the inside face of the bearing to reduce clutch nut wear and heat. Placed a kyosho engine washer on the end.
- Placed 30mm screws for the screws connecting the towers to the bulkheads so I could placed nuts on the end in case the screws back out. (I would rather bend a tower than have the tower come off the bulkhead which happened to my losi 8ight T during a race)
- Made my own aluminum bashplates front and rear and used 4 X 16 mm screws through the chassis
- Removed the 2 mm plastic washer from under the ackerman plate and place 2mm wrth of 3 X 6 mm washers under the steering knuckle so the nut would not touch the front / rear ali lower arm pin holders.
- Replaced the wood screws with hex flat head screws. Wood screws on an RC car is criminal.
- Used 8 X 10 mm shims on all the wheels to reduce wheel movement due to the pins wearing.
- Used 8 X 10 mm shims on the diffs as per the instructions, nut also shimmed the pinion gear. No point shimming the diff with out the pinion gear.
- Every nut has a washer behind it to stop the nut digging into the plastics
- Rear and front body mounts have the plastic locater removed and replaced with long set screws. I have recently tried using Hong Nor/Jammin body mounts and they fit perfect.
- Replaced the rubber tank mounts because the break down from the fuel spills. I place a small piece of fuel tube through the plastic lug and place a GMK fat boy O ring either side. This allows enough movement, but is substantially more stable than the original tank mounts. I found with the excess movement of the tank it would hit the break rods.
There are many more areas that got modded for strength and reliability.
Maybe the pro racers just use new parts all the time and expect to mod as they build???
I know everything on mine has been meticulously studied for the best results.
X Ray why not take a look at this list and make some running changes. It's free and sound advice.
PS What changes has everyone else made?