The only one I've ran was their older cheaper version of a buggy engine. The
Omega 21 Comp. It was a good solid engine if you swapped out the carb with something other than what it has. With the carb it had stock, it ran like crap from about 1/4 throttle to 3/4 throttle. The whole mid-range was gurgly regardless how you tuned it.
I had modified an OS 21 RG carb to fit. I had to mill the neck down about 3mm so it would fit, but it made it kind of thin, so it cracked on me over time. But for the 4-5 gallons I ran it with the OS carb, it would scream in my savage. I ran about 3 gallons with the original carb, but beings how it was, it was like a on/off switch instead of a throttle.
After fiddling with the OS carb, it was a whole new animal. Temps became stable, throttle response greatly improved but the mid-range for about 1/8th of the throttle was still a bit blubbery until it hit about 240, then it would smooth out through the whole RPM range.
I think I probably ran a total of 8 gallons or so through that engine and it still has a tight fit at TDC. I got an air leak in it after cracking the carb body, so I jb welded the carb on. But the carb neck bolt leaks and I bought a new OS 21 RG in the mean time and put it on. I'll go back to the Omega when I need to. I have a spare piston/sleeve laying around...
