Thanks for the response, Byrons is a solid fuel so that was not the cause. You might want to take a look at your break in procedure though. I've mentioned this several times on the thread but so called "factory settings" on carburetors are not "break in" settings. There are way too many variables that will not allow a guy in Italy (or Japan or China depending on where your brand of engine is made) to pick a needle setting to put on the carburetor before it leaves the factory that will guarantee a rich setting for you running your specific type of plug, fuel, pipe, length of fuel line and atmospheric conditions. These engines have to be tuned after being installed by you to a rich setting. Running "factory settings" for break in is like playing Russian Roulette, sometimes you will be fine and sometimes things will go wrong. But why take the chance? Try following my break in procedure that I posted in the thread if you do not have a system that you normally use or are unsure no how to do this. If you have any specific questions or need more help please do not hesitate to ask!

Regards,

Ron