I like mine so far. It sounds big and deep toned for an 80cc engine, and has torque.
Box said 24.80 lbs shipping weight. It's heavy, but not too heavy for a bike or trailer.
It runs good, but I still have to break it in on a bike when I finish my build. Nice engine, the build quality I observed doesn't seem as good as my Lifan 6.5HP, although, they are similar. I had to remove the gas tank to bend a metal bracket to get the idle right, and the throttle screw was so tight you couldn't move the throttle lever at all. Once I made those fixes, everything is good from there. It revs fast and works great with the 2300RPM Hillard clutch I have for it.
If you want to use this engine, give it a shot. I will be using the 2.5HP hoping to get much more than the 100MPG of the 6.5HP engine.
The 80cc 2.5HP is cheap compared to a typical 35 or 50cc 4-stroke bike motor, so you get a good deal, and more HP for your Dollar.
However, you still can't beat the HP/$ of the 6.5HP. However, size and weight has consequences, so that's why I'm going with the smaller and lighter 2.5HP instead for my 2nd build.