I have seen runtimes vary from 8-12 minutes.... My favorite budget pipe is the OFNA 086...from the Nova lineup a 2096 or 9886...The engine seems to prefer a very short manifold....On smaller technical tracks the engine can get amazing runtimes, but on our larger wide open track the runtimes drop, but to be fair no engines get great runtimes on our track....The long stroke of this engine gives it a very unique feel, its powerband pulls very strong and linear from a very low RPM, which gives the truggy the ability to effortlessly clear short run obstacles that it normally would not be able to do.....