Question??? What makes a GT! or 2 "about as pure plug and play as you'll find"? I haven't seen the kit first hand, but have done research. Yes the GT1 or 2 might be better then the ole OEM out of the box Chinese engine... the cheap ones. What difference I do read (if represented right) is the fact that ..
From seller site...
"The new 2010 edition comes with a larger exhaust port on the cylinder body for less restriction in air flow, creating more boost in power and speed and a larger front mount that is compatible with bigger bicycle frame sizes. This engine kit also comes with an upgraded high performance CNS carburetor that is designed to improve air flow and efficiency with a larger vent intake, low profile cone-style air filter and the new high quality EPA Good Year fuel line. Another great improvement is the upgraded muffler with built in heat shield for less heat and a longer Palladium cartridge for an extra quite muffler. Newly developed with all the latest components available, these engines are the highest quality and highest performing engines on the market today. Often referred to as the "Rolls Royce" of bicycle engine kits, the Grubee name is well known for the quality and workmanship that goes behind each kit. Have you tried the rest? Now try the best!"
This doesn't make it any more P&P. Both are mounted the same, both have the basic same (exterior) case. Both have to be fitted to the frame. For all piratical purposes the exterior of these engines are all the same. Don't get me wrong, I'm not putting them down....but what makes them any better at P&P?
Years ago I had a customer come to me. He had noise coming from a Chevy V 8 that was (factory re built.. so called professional re builders) rebuilt and someone had installed it for him. I'd bet the engine didn't have 10,000 miles on it....low time. Keep in mind that every small block (265 (some), 267, 283, 302, 305, 307, 327, 350) Chevy engine back then for the most part mounted EXACTLY the same...same engine mount holes, just like these Chinese engines. That's what made them so nice...P&P larger CI engine for a smaller CI, some with minor mods.
Well I tore it apart and what I found was that the engine re builder used the cheapest parts on the market, so cheap that the piston didn't have any skirt. In conclusion, what's on the inside can make a difference... on the outside..No. One installs the same as the other.
Product Requirements
For installing this kit buyer may need some basic hardware skills, tools, and take around 2-3 hours to install and do some adjustments.