Stupid mistake caused flat

Hi all I really did a stupid thing today. I was checking tire pressures. And decided that the rear tire 90 degree elbow should be turned outward from brake disc for easier access. Well I did this checked my pressure was going to go on a nice Sunday ride and got about 2miles and my rear tire went almost flat.
1.I maybe have to replace valve stem??
2. What is the proper position for elbow away from brake disc or towards.? Pain in butt to check if it is aimed toward brake disc.
Thanks

Mine points to the disc and dont have a problem, I use a garage type one on a flexi hose

It faces the disc side. There is a small plastic part that locks to rim to hold valve stem most likely yours is missing. It's damaged if loosing pressure. It's a pain checking that thing because it flexes and it's hard to reach.
I installed aluminum 90 deg. stems but had to rotate the rear one slightly to clear that raised part that holds stem holder. Look nice and don't flex trying to check pressure. You can't win facing the stems left or right because brake discs are on opposite sides.

Thank you for reply. I did learn a new lesson from all this what it feels like to have a tire go flat.
Carry plenty of quarters with you not just for parking but air stations
Learning to remove rear tire. Watched a video and tried to follow manual.

The stem faces the brake rotor because if you install it towards the left, it would strike the drive housing. The stem is secured to the mount on the wheel to prevent flexing of the stem while the wheel is spinning. I have a tire pressure monitoring system (TPMS) mounted to my valve stem and needs the stem mount. I love my TPMS! I no longer have to lay down on the ground to check the tire pressure before each and every ride. Just need to inspect the tire once a mount which is easy when bike on center stand.

"I have a tire pressure monitoring system (TPMS) mounted to my valve stem and needs the stem mount. I love my TPMS!"

This is interesting. What do you use? A quick Google search revealed a couple systems that work with Bluetooth and replace valve stems, with readings sent to a mobile app.

Mine is a FOBO Motorcycle tire pressure monitoring system. It replaces the value stem cap. Communicates to smart phone app via BlueTooth. Safe to use with Ride-On sealer/balancer. It alerts me when the pressure is above or below my set range. It even has a loud alarm it your tire pressure goes to zero.

"Mine is a FOBO Motorcycle tire pressure monitoring system."

Thanks for the info. I perused FOBO's website. That is a slick product!

Unfortunately I have a rubber stem on the front tire. Since FOBO says they are not liable for any "untoward consequences" with rubber stems, I will wait until my next new set of tires for a metal stem and some FOBO's.

And little by little, we will drag the trusty Silver Wing into a new age of technology. ;o)

I have the Steelmate TPMS - swear by it. You can still use them with a rubber stem and then replace with a steel stem when next you change the tyre. Bluetooth connection to the unit.
The digital readout is mounted in my dash - reads front & back alternately and flashes red with an audible warning if it goes above/below my settings.
I've discovered my tyre pressure changes as much as 20psi on a ride.

I have my FOBO system mounted on the original stems including the rubber stems on the front. I will change metal when I change my front tire soon. I didn't want to mount anything to my steering. Mine has a smartphone app.

Thanks all. I have to have this rear wheel stem replaced since I damaged it. Now I have learned a new trick. How to remove rear wheel looked like a pain at first, but Ince started makes sense. I hope Iron Pony can supply me with new metal stem and are the supports available on line somewhere.

Partzilla is your friend. Number 9 is the 90° stem, # 10 is the support (which may or may not fit an aftermarket stem)

https://www.partzilla.com/catalog/honda/scooter/2003/fsc600d-ac-silver-wing/rear-wheel

Many years ago, based on a tip from another forum user, I bought a 12" hose extension from an RV supply shop. They make them for RVs which have dual rear tires so you can reach the inner tire. It makes it a lot easier when checking the pressure and when inflating. Of course, a TPMS would make it even easier to check the pressure, but that's not in my budget yet.