after what I went through with the OS .25 FX I bought off of ebay , I would have not bought this engine . It seems to me , even after changing parts on an engine , as I have done on 2 OS engines, they never run as if the where new. I hope you have better luck with your .46 FX . I bought mine new almost a year ago and I still feel that POP ! when turning it past TDC. What a power house this engine is and it is not heavy at all.