Hey, how is that #420 chain running? Does it run fine, is there any problem? I think I have a #420 chain somewhere that came extra with my racing kart. Let me know if you run into any problems with it.I think it was #415. I had a left over #420 chain and put that on. its much much wider than stock chain and moves side to side a bit on the sprocket buts seems to work ok. I might have to replace it though if issues occur.