Not really. You need a gearbox to give you reverse, whether it's a box in the driveline, or the engine and gearbox off a quad or sled that has reverse.
The only engine that I know of that can be reversed is a two-stroke from older gas golf carts. These golf carts reversed by shutting off the engine and restarting in reverse.
If you really want to get creative and try something fun... here is ONE way that you can get reverse "pretty cheap": find a way to put a pulley on your engine shaft that doesn't interfere with your current clutch. Then... put a belt that "crisscrosses" between the two pulleys that is too-loose between your new pulley and a pulley on your axle. Set up a "belt-tightener" system using an idler pulley and when you tighten the idler pulley up... you will get reverse. In the picture attached you can see what I mean by "crisscrossing" the belt to get reverse.