I picked up an X-15 and it is in overall decent shape for it's age. One of the bearings is gone for the pedals. Is that something that can be replaced? On the back around the lights there is a hole. Was there supposed to be an exhaust pipe coming out? I will post pictures later. Thanks email me @ email@example.com
Unfortunately, these are very rare and I do not know of any reproduction parts being available for them at all. Your best bet may be trying to find another one for parts and/or fabricating parts for the restoration. If you do happen to find a source of parts or find parts that work well for your application, please do post your findings on this site so that others can find help with their projects as well. Thanks for posting and good luck with your project. We would all be interested to see your progress as you move along with the restoration.
You can get replacement bearings for just about anything at your local NAPA auto parts store. The pedal bearings for the X15 trike are simple "caged ball" type bearings that wear out quickly, especially if they're not oiled regularly. If you still have one of the old ones, remove it and take it to NAPA, and they can fix you up with a better quality replacement. If you cant get it out in one piece, just measure the diameter and width of the outside of the bearing cage, and the diameter of the pedal / axle shaft and give it to the guy behind the counter. Remember that the pedal / axle shaft is bent in order to form the pedal assembly, so get a bearing that is a little bigger than the diameter of the shaft. If you get it the exact same size, you won't be able to slide the bearing past the bends in the shaft.
The hole that's in the back of the frame of the X-15 is where the back-end of the steering shaft rests. Although I have seen a picture of an X-15 with a red plastic piece sticking out of that hole, I don't believe it came from Mattel like that.
I still have my X-15 that I got brand-new when I was 3 years old, and I don't remember there ever being anything in that hole. However, I do remember thinking that it might be cool to stuff some paper into the hole and set it ablaze, so there would be actual flames coming from the "exhaust". Don't worry -- I never actually did it... probably because I couldn't find anything to light the paper with when I was a wee tot. Hee-hee!