Speed increase for electric Yamaha PTV

[Raptorbob]

My 2018 Yamaha PTV just came back form 3 days in the shop to get a speed code increase from 15MPH to around 20MPH. I was told that everything they tried was not successful and since the cart had a factory lift kit Yamaha had obviously locked out the controller to preclude a speed increase.
The shop was recommending installing speed gears in the diff. I asked about installing an Alltrax controller and was told that their experience was that some of the installations were causing flaky operation.
Does anyone have experience with Alltrax in a Yamaha DRIVE2 installation?
Gears, aftermarket controller or another Yamaha controller that would allow speed code installation. These are my choices, probably all of these will negate the factory warranty so I am looking for advice on the best choice.

[cgtech]

What exact model? (This part is a big deal). In some instances that is true. Let's figure this out before you jump into HS gears. All options "may" void warranty. But let's clarify first. Regular golf cart size tires? Which model? What size tires were equiped from factory? What's on it now? The dealer probably changed that. If it's "big lifted & big tires" just say so now to clear it up. Please list exact tire size. I wouldn't mind a SN if you are up for that, even the first 4 digits (J**-*-----), just the stars, likely don't need the last digits. Please don't give me a sticker part number, J**-<not a letter here. The character after the "-" dash cannot be a "letter". And after the dash will be !6 numbers!, No dashes or letters after that.

Sorry, but I am so tired of stupid "sticker part numbers" being told as Serial Numbers!

The sticker that says production date DOES NOT have the serial number on it.

I am more than willing to help, but help me help you!

[Raptorbob]

Serial # JOE-100532.
4 passenger, probably a moderate lift and I bought it new and was told it came that way from Yamaha. It has lights, turn signal and a brush guard in the front.
Tire size 205/65 10. Right now floor boarded it does 15mph.
Owners manual states it is DR2E18 PTV

[cgtech]

I have heard of factory lifted carts not being eligible for PTV speed. But, I didn't see anything that specifically lead me to believe it can't. You do have a throttle return spring recall that hasn't been registered as completed.

[Raptorbob]

Recall was done. I was told that if i went with the high speed gears they would warranty the cart for the balance of the mfg. warranty since factory warranty would be void. Do you have an opinion on gears vs aftermarket controller?

[cgtech]

I have never used the Navitas aftermarket controller for AC drives yet. But it probably would be better than gears (which will hurt power)

[19DRIVE2]

I have a 2019 and went through the same issue. They can not program it higher than 15 mph due to it being lifted. I put a navitas controller on mine. The TAC 1.0 I now have it set to do 25 mph. It is capable of 32mph but has to be programmed for that. I set up as a dealer with them so if you are interested I can help you out on the price. Just let me know if you're interested or have any questions.