250-500cc How many hours on a WR 300 piston?

I found out compression test only test ring seal not condition of piston. I just put ome 144 kit on my 08 cr125 and had ran great for about ten hours and had about 165 psi comp still on compression test after last ride so I figure I was good till mid next season. Wrong. Took pipe off to do some work on powervalve and looked in exhaust and seen major scrapes on piston so I took top end off and found ring was stuck and major wear on piston and cylinder. Looking at piston I can see there is still not any blow by rings but what cause ring to stick is still unknown. I sent piston and cyclinder to Scott to see what he can figure out. I was running a 32-1 mix on Yamalube with a premium VPc12 mix to around 96 octane. The plug looked good light tan and jetting seemed close if not little rich, spooge still out of silencer a little and bike took couple turns to clean out good when starting laps. I always warmed up bike while changing into gear. So do not rely just on compression test to get idea what shape piston is in. I got lucky and found it before more damage was done. I only ride motocross but I am only c class rider.

Not bhp... WHP my friends

Oh, sorry, wrong spelling my friend! Of course it´s Whp! It´s a Husky!

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Also dont forget that a big bore 2 strokes need quality mix oil and more oil than a small bore 2 strokes.

I use at least 3%, especially on the ice. No spooge, works perfect! There is no reason for me to go under that as it works without problems.

For me, 40/1 or 2.5% with Mothul 800.