My son is 16 yrs old. He likes to ride easy trails but isn't interested in racing with me. He learned on a TTR125 when he was 12 yrs old. He just isn't interested in competing or riding in a race environment. He did a few laps at an enduro sprint race last year but didn't like the challenging terrain or people yelling for him to pull over.

I would like for him to come with me to one of the West Texas restart enduros but I'm not sure how self sufficient he would be in the event of a mechanical problem.

Any tips/ideas?

Do some family ride days, so he can ride with others in his age group/skill level.
Racing isn't for everyone.

Yea, I think it would help alot if he had a riding buddy.

"Yea, I think it would help alot if he had a riding buddy."

Would totally agree with this.

Yeah, same age friends will make it much more interesting for your kid. 16 yo is the age when you don't really want to hand out with your parents a lot just face it.
On the other hand, kids don't often share the interest of their parents with the same enthusiasm. You should always give a choice to your kids, steer them other directions(but keep him off from dancing...just kidding).
If you want him to stay in the motorsports perhaps you should introduce him to atv or even truck racing and prerunning. I've seen many kids around Austin building insane trucks and baja bugs, it's old school but they dig it, it's something new for them. And it may be less dangerous than professional motocross.

It's a modern world and you can motivate him with videos and sites like this:

ATV https://www.americanmotorcyclist.com/Racing/ATV-Racing
BAJA 1000 https://www.redbull.com/int-en/baja-1000-interesting-facts
Prerunner and Desert trucks https://autocarspec.com/what-is-a-prerunner-truck-and-how-to-build-it.html

Hi there. Racing is so cool that I even don't know why you need to motivate him. Just show him a couple of videos or better give him a ride.

If he's not gravitating to naturally, it may not be his thing.

My dad was a HS Football coach. He rode with me as a kid, but he was Football through and through. I never had the hot blooded interest in Football after my freshman year... even with all the wicked hits I had landed. It was just was not my natural passion. Instead...I was infatuated with my motorbike. I've always had a hard on for motorbikes. That was naturally MY thing.
Dad still loves his football.

Have girls who are so addicted to make-up now and no one is even interested in any sports. Just trust him he can do it for sure whatever problem he would encounter he can face it. Sometimes they are stronger when we are not physically beside them.