Lets all say it together. Thunder Tiger, Thunder Tiger, Thunder Tiger. I am no engine pro by any mean, but of the 4 engines I have, only the 2 TT pro 46 run without any problem. I have yet to deadstick with one and the break in is a no brainer. I have yet to even touch the low end needle valve on either one. The factory setting is perfect. Buy a tower hobbies muffler for it and it is an absolute beast.