My new engine works well and has a ton of compression, but I don't think the carburetor is good. I am using my old carburetor from the old engine, as the new engine did not include a carburetor. The engine will only start with the intake hole where the air filter pipe goes blocked completely. It will not suck gas through the tube without this blocked with a hand. If you put the air filter tube on, it will not even really try to start. But when you block it, it will fire up and run great, and gas comes out of the hole and through the tube. I was thinking maybe it was a problem with the vacuum system or the carb was bad. I have cleaned it and everything, but it did not help at all. It seams that the carb does not want to pull gas through the fuel tube at all with just the air filter tube on. I think it is because maybe the carb is bad or has a problem. I would appreciate any suggestions on the carb or vaccume system.