I have two Evo 10's with the original carbs on them. Both are fitted to planes that require them to be fitted inverted and while they have been running Ok I have always considered the pump carb as a better way to go.<br>I bought two carbs from Horizon and when they arrived immediately took one of my motors out of the plane and fitted the new carb. Whole operation took less than an hour and I was happy with the final product. Fitted the motor to my test stand and fired the motor up, worked like a charm and ran up and down the rpm with no hitches. Very pleased with the mod.&nbsp;<br>Then fitted it back into the plane and took the plane down to the field for a test flight. Unfortunately nothing happened, could not get the motor to start no matter what I tried. After much frustration I packed up and decided to investigate on my workbench where I have sufficient tools.&nbsp;<br>I always check electrics first as that is a common problem. Using the Rxcel tester I determined that the sensor worked, the CDI was fine but when I checked for a spark no luck. Changed plugs and still no spark so changed CDI units from the other motor and all was good, nice spark and that allowed me to try again. Still no luck with the starting. Starter was actually getting warm with the workout. Took the plug out and no fuel! So put the plug back in and rigged a means to cover and uncover the carb air inlet with out getting my hands too close to the prop. This time with the air inlet closed the engine fired up but only ran for a few seconds. This was a good indication of not enough fuel getting through. So checked the low end needle adjustment and found it was wound in tight, tried to wind it back out but it just spun freely as though it was sheered off. Wondering if there was a bit of binding on the throttle body and as I tested my throttle limits I wound the unit in? Either way it was not working. So grabbed the other carb that was destined for my second motor and fitted that, checked the low end needle and it was a lot further out, so hopefully it was in the right factory setting. Once everything was connected I put the starter on and within seconds had a happily running engine that ran up and down through the rpms beautifully &nbsp;<br>Now I have a carb that is stuffed and wonder if Horizon will fix or replace for me? Looks like I will also be needing a new CDI unit as well.<br>Looking forward to flying this Sunday though should be a lot of fun.<br>