i want to know is a honda three wheller engine is the same as a trail 70. The reason i ask is cause i have a QA 50 and i know a honda trail 70 engine will bolt in, want to know is a three wheeler engine would bolt in too.

 

I think the atc 70 has different trannyu ratio's then the trail 70 I have a SL70 and it has a clutch and the atc 70 doesn't I used to have a atc 70 and it was ok for a smaller guy or gal but I think with the trail 70 motor the ratio's will only make it worse. WELL REMEMBER u CAN PRACTICE PRACTICE AND PRACTICE AND u STILL CAN'T BEAT ME

 

The ATC70 engine is very similar to the SL70 engine, one point to note is that the crank is different 'cos it has to accomodate the zip starter.
I have a Z50 which I grafted on a head and barrel from an atc 70, it works fine. I'm sure you will find an ATC70 shoud just bolt in to your QA50 frame.
How about this for a twist. I know a guy who grafted a 200X engine into an ATC70 frame. I may have a photo somewhere if you are interested. By the way, this was not just a bolt in swap, the engine needed radical modification to make it fit but stangely enough the frame remained almost standard.