Time Surfers 1 & 2 (Space Bingo/Orbit Wipeout) by Tony Abbott - Vintage Paperbacks Set

Ned Banks is miserable.  He's the new kid in school--and he sticks out like a sore thumb.  His life is going downhill fast.  Until something happens.  Ned's not  sure how he did it--but he beamed two kids from the year 2099 into his bedroom closet!  Roop and Suzi are Time Surfers--cool kids who travel through time.  And they want Ned to join them!  Of course Ned says yes.  He's ready for excitement! Action! But he might get more than he bargained for.

Then, Ned expects his best pal Ernie for a week visit until an urgent call from Time Surfers Roop and Suzi. On Centaur One, an abandoned space station, awaits Vorg-the biggest villian of the century, plus evil Klenn from Ned's comic books. If bad guys come to life, can hero Zontar as well? Otherwise the Time Surfers might be trapped forever!