What is the size of the original wheel?

Original 7px is 41mm, optional is 46mm

Original 4px is 41mm / foam O/D 46mm, 7px is 41mm / foam O/D 48mm. So id imagine the 46mm wheel might be 51/52mm with foam?

How to change language of telemetry speech
 

Does anyone have a FUTM1725 charger they'd sell? This is the LiFe wall charger for the 4PX. They are out of stock and I could use one.

PM me!

let me check if i still have it.

Thanks - let me know.

I think you need flash English firmware, not Japan.
Ripmax - Futaba Upgrade T4PX Transmitter
https://futabausa.com/product-inform...are-downloads/

Which receiver provides the fastest response time with the 4px transmitter?

304SB with telemetry off + in 4PX: Response ON, Fastest, Fastest, Racing mode ON
I suspect that 334 from 7PX will work equally fast.
https://www.rctech.net/forum/radio-e...m-results.html

Rf error
 

https://cimg5.ibsrv.net/gimg/www.rct...83d2b747e7.jpg
Hi guys, my friend encounter this error on his 4px, he is not charging battery on the tx and have try unplug and plug in battery few times, still same.
As per manual need to send in for repair.
Any way can fix this, thanks in advance

I would try different battery before repair.

Thanks, I've done this and it worked, also learned a few things about saving model data into the SD card. I've learned heaps about the 4PX and thank you very much!

has the 4px been discontinued? new model coming?

Yes discontinued, the 7PX took its spot.

Anyone has an Idea on how much it cost to replace the screen on the 4px? I dropped a few months back and damaged the screen. Still works and I can see about 75% of the image. I already bought a 7px and if the repair its priced reasonable, Ill get my 4px repaired and keep it as a back up or as a loaner.