I used to have a 1986 phazer. It was a pretty neat sled but it had seen better days! The rear shocks were blown out and everything was worn out but it ran like a raped ape! You will be surprised how fast it is for just being a 485. It was light and nimble, but even with new carbides it won't have a very good turning radius.
As for reliability, I remember breaking the steering column off the frame by jumping it so much, but it looked like it was poorly welded together by someone beforehand anyways. I'm pretty sure one of the crank seals went bad and i got rid of it after that. It was a really fun sled and assuming you have the older model (85-96?) you will love it!