I BEEN RUNNING YAMALUBE 20W40 IN MY 06 RAPTOR 700 SINCE I BOUGHT IT BRAND NEW.WELL BROKEN IN BY NOW I WAS THINKING ABOUT SWITCHING TO SEMI-SYNTHETIC 10W-50,IS THIS GOOD OR BAD? WHAT'S THE DIFFERENCE BETWEEN THE TWO? NOTE THAT MY QUAD HAS BEEN MODED ALITTEL.FULL YOSH EXHAUST AND K&N FILTER, PC3. THANK GUY'S.

 

I would be more concerned with the fact that you are changing oil viscosity. Running 50 weight may hurt your engine if it was built with tight tolerances. As for synthetic, you should not have an issue unless it is "energy conserving". I try to run synthetic in everything I own. There are several motorcycle articles on synthetic (with lots of info) you should be able to find if you search the web.