I've got the blue Schwinn Link from Wal-mart, and can give a fair review of it...........................................
I've been riding it everyday for over 6 months and put 4,200 miles on it on my friction drive setup.
It is a decent bike, however like any bicycle that is made by pacific cycle for big box retailers, it is not the best.
This is what has broke or is its weak points.
The bottombrackets on all pacific cycles(schwinn, GT) that big box retail shops sell are crap. Mine is about shot, I had a GT before made my Pacific Cycle that I bought from SportsAuthority and same thing. The bottombrackets do not last.
The threaded thru axle locked up on it. It was due to the super dry conditions of the Florida Keys though. The salty/humid air sucks/drys the lubricant out of hub.
I broke 5 teeth of one of the cogs on the cassette. The cassette is made of an inferior metal.
Everything else has been flawless, and the bike is still running. It is a good bike to put a motor on, not sure if the 66cc engine kit will fit in the frame and the top tube would be a challenge to mount the 66cc kit gas tank. The bike will probably last longer than the 66/80cc engine kit, you might wanna consider a friction kit for greater reliability.
Bottomline: For $159.00 new it is a sensible buy for putting an engine on.