When they are available, they come with the motors.
http://replacementparts-skyrockettoys-com.3dcartstores.com/2450-GPS-Motor-and-gear-set_p_143.html
Unfortunately, it has this on the site: Will not be restocked after next restock . However, I believe the small pinion on the journey is the same size as the 2450, but the large pinion is not.
The small pinion is 13T so you can search google for parts.
Ya I’ve looked into sky viper and know what you’re saying. I’ve been waiting 3+ months and wasn’t very nice in my last email . I’ve not even heard back from them… I’ve checked other sites and nobody has a 4mm. However- Somebody had to make them. Lol. Thanks for your reply
I might try to order the motor and board Det for $17 if they’re talking to me 
I ordered the motors And board for the Journey. I’ll post whether they’re the right pinions. I found the big gears for It
Ok. Here is what I have decided to go with … I want to use the electronics from my 2450 and build my own … My Q is what all do I have to do to make it brushless and what size frame should I use … These things started as toys to me But has become a serious hobby and would like to end up someday as an aerial photography business
I also realize that I need better than sky viper
Honestly, my guess is that was the exact reason ArduPilot was excited to partner with Sky Viper. To get people into the hobby, and interested in AP. 
And magically pull the rug out from under them……… 
maniacally
There…fixed it for ya! lol
That’s what happened! One day I was buying a “mass market” priced drone that I was less likely to lose…
…and now I find myself trying to hack a DJI OEM f/c (Lite implementation?) to see if it is possible to make it play nice with Ardupilot. You folks have been so helpful with the SV, which I continue to “play” with, that I thought I’d ask around, (if appropriate). Or look for suggestions as to where I might research. Thanks se
Still looking for main gear/shaft for the v2450. Limited flying’s the result. Hence the query.
Did you use (2) for each shaft?
Finally the gears are back in stock with the motor kits for the v2450 at sky viper spare parts page. I grabbed a few sets.
It’s smaller than the v2450 ( pinion gear)
One for each prop. Top side under the big gear. When you drill the hole for the bearing seat it should be only deep enough to fit the bearing. I drilled one of them too deep and it still worked ok. To deep and you are removing material you need for prop shaft support. I used the non-flange bearing. I bought flange bearings also, but they are not a good solution because of the flange. Be careful. The bit will want to dig into the plastic. As I drilled the bushing came out the other side, but I had to push out a couple of them. So you can remove the bushing and shorten it to make up for the bearing. You need enough bushing to support the c-clip end of the shaft. Cut slightly more than the depth of the bearing and re-insert until flush at the bottom. Try to get a good finish on the bushing since the drilling and cutting tends to rough it up and deform it. I used a dremel tool to cut the bushing to length. There was no change in flying time, but it is quieter and has less vibration. Good luck. Sorry for the late reply as I don’t check the email account for this group very often.
Regards, Tim
Curious if you have a link or spec for the bearings you used? thx…
As I recall they are basic metal 2.5x5mm bearings. Here’s a link. Been a while since I ordered them, but this looks familiar. Do not use the flange bearing as there is little clearance between prop gear and frame. You will notice vibrations decrease, flight time stays the same.
https://www.avidrc.com/product/1/bearings/174/2x5x25-Metal-MR52ZZ-bearings.html
Thanks! I picked up several replacement frames, one of which I will keep brushed. I measure the prop shaft at 1.8mm? Am going to try a different bearing number and will let you kinow. No flange tho! ;- ) Consistent motor to motor power delivery is my main goal here. Vibration reduction is key…se
Good luck. Be careful drilling the plastic since the bit will want to grab and pull. Fixture and drill press would be best. I did it by hand with 5mm bit. I probably didn’t get a good centerline.
Off topic: I have more than one of the v2450GPS that have unstable yaw. Even when sitting still. View the web page System Status-IMU and the yaw is counting up or down especially after making a move. This causes the drone to rotate while in flight. In a short time it will move 10 to 30 degrees so stick actions become confusing. The only work around I can imagine is going to Super Simple Mode.
Any ideas?
Thanks, Tim
Hey Tim, I have had similar issues. When you say “sitting still/making a move” you mean while hovering? Do you get the same fluctuation in readings when it is on the ground? I noticed one of my quads arms vibrating excessively while hovering (bent prop shaft). The stability of the sensors seems quite vulnerable to vibration, and the hold performance (all sensors) has improved after straightening/balancing and bracing the arms with a strut system. Oh, and after getting through all mag/accel calibration. n’joy! se
p.s I do understand about drilling plastic, as I once sold and repaired HDPE sea kayaks. Yes on the press if can. Step Drill? Three fluted bit? Dremel w/grinder bit? Or most likely, carve it out with an Xacto knife?!? I’ll let you know what seems to work out best. Thanks again.
I’ve had vibration issues and the bearings helped. As to yaw instability the answer is yes to both your questions. When unarmed you can see the yaw data moving either negative or positive while the viper sits still or if you move it by hand the yaw data keeps moving even after the viper is still. While hovering this yaw instability is translated as constant slow rotation. This rotation also occurs while flying which really screws with your head since you assume it’s flying straight. As this yaw happens the pitch and roll orientation swap from the pilot point of view.
I like the viper, but it’s not robust. I think the high temp camera board under the main board is cooking the IMU.