Because they are a pain in the butt to tunem and they wont hold a tune for nothing. i have seen, in a bunch of occasions, people get so mad with them they lean them out, start them up, and hold wide open till it blows.

i also had one and it would run amazing and you will shut it off and when you crank it back for the next heat the tune would be off, to much tuning for me.

i loved my GRP but they are no longer a company. also have had STS, Vspec, OS RG, Jammin JPX 21, and Nova plus 4 is by far the best engine i ever ran, it wasnt mine but i tried one and ill be getting one soon.

but now that i have tried Nova ill never run anything else, im running a 150 buck nova and it pulls my jammin truggy no problem and tune and leave it.

also Alpha engines are good too, for a buggy the green head one will be the best.<br type="_moz" />