Jaka,I've talked to you in the past and have done everything you've said on top of my own long experience with 2 stroke engines. I run the engine on the rich side and still no luck. I talked to a guy who sells varsane products(perry carbs). He's got one that will fit perfectly. I will try this next and that will be it. If the engine doesn't run well after this it will be pitched. I promised myself along time ago to stick with the stuff I know works because I've been burnt before. The guy at morris talked me into the combo of a hot hotts and this mvvs 49. Yes it was a good deal as far as rc goes. So once again I must promise myself to stick with the time proven engines. ya get what you pay for and this one is my last.