My 4.1 Savage was running great.. temps around 140 - 160. I installed a RD Logics Savage Twin Pipe W/Dual Stinger.. the tail pipe that comes out the back. The instructions said I would have to retune... First tank with the stinger the temp was very hot.. around 280... kept richening up the mixture... got it down to 210 - 220. At that point the screw was nearly flush like factory setting and it wouldn't shift into second gear because of no power. It seemed to like 250 - 260.. Still had smoke coming out the pipes and was shifting strong... I am scared of ruining the engine and as things are now will put the stock pipe back on. Any thoughts ???? Thanks !