Does return to stock pipes mean other changes?

[loweredisbetter]

I own a 1997 Heritage Classic. Since I bought it new I have run a Mikuni HSR42 carb, Andrews EV27 cam, Screamin' Eagle Selectable Curve ignition module, Screamin' Eagle single coil and Thunderheader pipe. Other than these things the motor is stock. I am thinking about going back to stock pipes mainly for less noise. The packing inside the Thunderheader is shot now so the pipe is even louder now than when new. My questions are: 1) how much power/torque will I lose? 2) will I have to modify other things to accomdate different pipes? I know these components work together. I've heard that the stock head pipes aren't so bad if you use decent mufflers. Incidentally an H-D factory rep told me that the Thunderheader pipe makes the engine run hotter, and I'd sure like to know if that is true because it just doesn't sound right. Any help would be greatly appreciated. My favorite wrench who put this package together for me and knew all these answers has retired and moved away. Thanks!!

[Mike]

Going back to the stock system may require MINOR jet changes in the carb. Everything else will work just fine. The ignition may want a similar small change, but run the most aggressive curve until/if detonation appears, then back down until it clears up. Two into Ones have been known to run hotter due to heat buildup at the merge collector. Typ. other things are done that cool the motor (timing, jetting, cams) offsetting that increase in heat, with the exh install. Argueably, the stock exh runs hot due to back pressure build up. esp. at the rear left to right split just off the head. You may actually pick up low end torque with the stock system giving better "seat o pants" feel. You will loose peak hp and tq (predict about 6 off each) but will have a broader/flatter torque curve. Remove the restriction in the "Y" pipe where the rear spigots down into the front when veiwed from the front of the front runner (where the front head pipe and rear y pipe join under the trans). This will help overall performance. The move to quiter pipes is good from a PC standpiont and will help demonstrate we are becoming aware of these issues with the public.
Thanks, Mike

[loweredisbetter]

Thanks for the excellent information. One more question though if you have time: I am assuming here that the Y-pipe to which you refer is part of the stock exhaust system used on dressers. My stock system is the staggered duals. Is there a restrictor in the crossover of my pipes? Thanks again for everything!

[Mike]

Your right, I lost track of what model we were talking about! :o Does not apply to your bike.
Thanks, Mike