Originally Posted by mugenize1

Well guys let me tell you my drama. I found the #7 and the #6 plugs for the mugen ninja mr-.21 on-road. I was told that this engine does not need 30% fuel, 25% was good, But if I was going to run 30% then I need to add a shim under the buttonhead just like wingracer said went to remove the the buttohead and the sleeve came off also I was thinking ok wiggle it off wrong had to heat it up to remove it when I looked at the piston it looked like some one hit with a hammer!!!!!!! the rod is still new not a dent or stretch because I checked it with one of the new ones I have. and enverytime I remove a plug I made sure the spring on the plug was not in the engine. So know I am out an engine and can not run. Looking into New blocks any ideas out there on what I should get I like navorossi plus 35 or is there something better.