My freind put me on to using the perry regulating pump. When I bought one I didn't even run it without the pump. They are easy to install and not to awful hard to tune either. I never had a problem with my engine. My friend who is a very experienced. engine man, had all kinds of dead sticks until he pumped the engine. Now it runs sweet just like it should. He has owned several big tigers and he won't even try to run one without pumping it. Everything else is left stock. The stock carb if fine once its tuned. Hope this helps. The pump is only about 25 bucks form tower. Happy flying