i have a 1980 CR 250 and i just put a new weisco piston and a set of rings in it and now when i ride it after about 45 minutes it just burns the plug up and it lose's its spark i mix my gas at 50:1 ive tried mixing at 40:1 i started out using a NGK B8ES spark plug then i moved up to a NGK B9ES and i even tried a resistor plug that was some weird NGK number and my needle valve is on the top notch please help thanks
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dont get weeded!
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dont get weeded!