My murnan ran great with little bottom and ballistic top for about 6 tanks of fuel, after leaning after breakin, Now it won't run over 2 mins on the track acts as if its leaning out or something. Tried 3 different carbs and 4 different plug ranges, changed fuel line and tanks, even removed high and low speed jets cleaned carb and reinstalled o'rings even changed carb mounting o'ring and backing plate oring, there seems to be no air leaks.. My smeltz richeys and topguns fires right up and will run till the till batts go dead if you keep filling the tank. What's all your buds setting even the mid jet???. If you don't care, I've tried everything I know and I think I can tune pretty good, and have never seen temps over 240 on 30%. The Murnan maybe an Ebay item to me!!!!! I'm sure I guess theres bad engines in everybodys work,, I must have been
lucky before, maybe??
I never seen any 15 engines faster than the 12's for 200 mm. I thought most 15's make alittle less HP than the 12's Most companys spend more money and time on 12's than the 15's. Never pay attention to those HP ratings.