Only reason I would recommend this gasket kit is because you have to use it when using an ATHENA kit with their head design. *I have used a complete ATHENA kit twice (piston, cyclinder, etc) on our personal race bikes (2008 & 2010 YZ125) -and also installed them for other riders with varying degrees of sucess but nothing better than OEM. I would not recommend this application for a MX racer and have seen limited sucess with GNCC type racing. Talking with other mechanics they have experienced the same things. Love it or hate it, no inbetween. The trend I have seen is lower rod bearings or thrust washers burn up which also leads to the crank stuffers melting. Yamaha does not sell the nylon OEM crank stuffers seprate which leaves you looking for a new or used crank with good stuffers= $$. Dont get me wrong, the gaskets are fine - it's all of it together that we have had preformance issues with.