I had this same problem and it was the battery.

Thanks! Fingers crossed mine's the same.

Does anyone have a Maxline offset aluminum wheel? If yes, do you like it?

I just picked one up and need receivers. Which ones work best. I was told to stay away from the fast.

2017 Updated data from Futaba Tech (Steve) just this morning:
A) Futaba Fasst Rx has lower Latency than S-Fhss Rx (he said my estimate of .03ms was "about accurate")

B) Fasst Rx's have nearly twice the Resolution of the S-Fhss Rx's

C) Fasst Rx's potentially drop fewer data packets.

D) Fasst Rx cost 2-3 times more (614E = $100 vs 204E = $40)

Can you translate that? Are you basically saying that fasst receivers are better by you pay much more?

No. Fasst rx's are faster due to the protocol used.

More importantly they have virtually twice the resolution.

Using a Fasst rx probably gets the 4PX around the M12 to possibly inbetween it and the M12S for latency. The resolution with a Fasst rx should be as good as the M12/M12s from the conversation.

It seems that the Sanwa systems have been using the Fasst type hybrid protocol (I believe it's a Dsm + Fhss type) for some time, even though Futaba appears to have been first to market with it. Sanwa seems to call it Fhss 3 and 4 instead of Fasst (probably due to Futaba patents/copyright). The differences between the two companies would be in the programming of their systems using the hybrid protocol. I told the Futaba tech that I didn't understand why Futaba was letting others dictate the terms of how their product was being characterized when they could have just released the info. The tech said that he would present this up the chain.

Note: I meant .3ms not
.003ms for the potential difference in latency between the Fasst and S-Fhss rx's. It should also be noted that the Futaba tech didn't have the exact differential figure, but he knew for certain that the Fasst rx is faster than the S-Fhss and thought my estimation sounded fair. Lol.

For me the virtual doubling of resolution (about 98% more roughly) is even more important than the decreased latency. That increased resolution, along with better error correction should really improve feel.

can anyone tell me why my R614FS receivers wont bind with my 4PX ???

It should work fine I believe. My 614E worked with no problem.

Therefore, assuming power is being given to the rx, , then I would check the following:

1) Fasst rx setting is selected under "Receiver" within the Tx menu and leave your Tx on at this menu.

2) When you turn on the Rx it should start flashing green.

3) When/If you get a message on your Tx asking you about resetting any failsafe say "Yes/Accept".

Your Rx should bind and the LED should turn solid green.
What is yours doing?

Then between FAAST vs T-FHSS?

T-Fhss is just Fhss with telemetry from everything I've been able to find. Information that I've come across indicates that there is an increase in latency with the telemetry turned on (you can turn it off in the Tx). The Fasst protocol is simply faster than the Fhss based protocol, whether it is S-Fhss, T-Fhss, or basic Fhss. Of the stock Fhss protocols from Futaba the S-Fhss is fastest.
This is of course for Futaba receivers; Sanwa receivers have a hybrid technology that is basically like the Fasst but they still call it Fhss (3&4).

I'm sure that a Futaba rep can chime in on all of this as well.

I've selected FASST 2.4 in receiver selection & followed procedures as instructed. The receiver stays red.I push the receiver button & it flashes red .then stays red.

If you purchase a Futaba in Australia beware that you will get no support from anyone in the U.S. or Australia.
I would not recommend Futaba after my recent experiences trying to get help. The wholesales dealer in W.A.apparently expects that all buyers to investigate the dealers to ascertain the origin of the products' importation.
They won't assist at all.
U.S. were slightly better but won't answer the support line & if you're from overseas , again, it's not their problem.
Sanwa next time for me I think.

Is it true that you can't run a lipo with this radio?

No idea.i have a life in it