Question: Can you anodise a KT 100 S cylinder head?  The clarification from the  AIDKA Technical committee is: Anodised cylinder heads are NOT allowed on KT 100 S engines.  Effective: 1st May 2019   Clarification of Rule: 11.3.1 KT 100 S specifications, Single KT 100S Piston Port Engine only as manufactured by Yamaha with standard external appearance( no left hand conversions) from carburetor inlet to barrel exhaust outlet. Piston port engine must retain piston induction ( no reed or rotary induction allowed). External modifications which do not in any way affect a performance gain are legal.  Maximum piston diameter is 55.0 mm. The use of thermal barrier coatings on or in the engine / engine components and, on or in exhaust components is prohibited. The use of anti-friction coatings on or in the engine / engine components is prohibited.   The Tech committee have considered the overall wording, discussed this and agreed not to allow anodized KT 100 S...