Modern Vespa

Here's one of my KR's in 3rd:

The selector piece that moves at the end of the shaft is flush on mine in 3rd.

I basically just need to know what selector box to order, which was stated above but it's also 100 bucks. I've seen others for more like 40.

Also from a previous post with the rear wheel off the ground mine doesn't click in neutral when spinning.

The selector box is prob not the issue. It would be almost obvious if there was an issue with it after inspecting the moving pieces inside. The selector can be very robust and I wouldn't start throwing money at it yet.
When changing the cruciform, the gear stack needed a good looking over for other symptoms of not staying in gear. Gears inspected for wear and tolerance and making sure everything is button up correctly. Been through the same problems to find out it was couple of issues.
Diagnose the problem first before buying parts. Opening the motor again should be easier since it's been done before. Check the gear stack tolerance and wear. Make sure the cruciform with the washer is on correctly and gears are back on in order. Once all is right and double checked button up and ride. If problem still occurs the next thing down the line is the selector box, cables, and shifter.

Good luck!

Looks like he just wants to ride it, in order to resist the temptation to toss it into a creek.
Having an incorrect box with play will cause his issue -- or rather, amplify other issues. It's a small investment, to maybe avoid opening things up again just now.

https://www.scootermercato.com/Scooter-Parts/Selector-Box-Complete/138880

Thank you Ray you're exactly right! Basically just trying to enjoy it for the summer if possible,as our riding season is short in Montana. Then do more extensive complete rebuild in the foul weather months. If another case crack is a must then so be it but definitely trying to avoid it for now.

I will say this. I've never come across any Vespa engine that had a completely worn out cruciform that also didn't have worn out damaged loose gears AND a gear stack that didn't need to be shimmed up tighter. It's almost as common as a worn pivot pin and an ovalled out selector arm hole in the selector box. Point being it's a whole package deal to have a solid, reliable, smooth shifting transmission. Which is also why an engine rebuild costs so much money.

Big win! Swapped the selector box, new pinchbolts, went for a rip and ZERO slipping out of gear. Very stoked. Now I can ride this summer and slowly improve things as we go. Best I can diagnose is the old box (a) may have been wrong and (b) had some play in the arm that the new one didn't. Honestly don't care what the issue was though lol!

On to swapping the front brake cable, checking everything in front for tightness, etc.

Can I swap the sight glass without removing the tank(s) and all?

Congrats.

And no, you have to remove the tank from frame to swap sight glass.

Love to cross-reference MA and MV, good to see you here Brycen.

What up Dirty D! I must say this P200 despite the struggles is waaay better than that damn 40mph Bravo hahaha

Hahah, yeah man. To say that Vespa/Piaggio's quality jumps from moped to scoot is an understatement. That said, I love them all.

I think I asked you this already....Instagram?

Yeah man, we delved into moped chat on IG.

Got all my lights working tonight except for my left side blinkers. Front and rear. Any advice on where to start digging?

Awesome.

When you get around to it, don't go cheap on the front brake cable/outer set -- and don't just change the cable. The outer can be easily pulled using your current outer and a spool of solid 18 gauge picture hanging wire. Far better communication between the lever and the pads will result.

PTFE/Teflon* and stainless should be in its description or bail out.

*PTFE is Teflon. The name Teflon is trademarked.

Already have a good cable that came with my selector box but can you make my left blinkers work lol?

Flasher or switch if you've checked your bulbs already. Flasher is cheaper and easier to try first. My px needed both.

Good work on getting the gearbox sorted out.

Vespa gears can have a bit of an agricultural feel, but even the old boxes work nicely when in good order. When you have ridden one for a bit, it comes naturally and feels smooth. When you start missing shifts and it comes to your attention there is probably something wrong.