Stock Muffler -- Stock Head Pipe -- End Plate On
STOCK EXHAUST => CLICK FOR PIC

Pros:

Quiet noise level.

Cons:

Stock muffler is very heavy.
Stock muffler with end plate on inhibits potential stock power.
<Kirk - Stock head pipe is very restrictive>
Cost: No extra cost.
 
Stock Muffler -- Stock Head Pipe -- End Plate Removed
Pros: Acceptable noise level.
About five more horse power over stock muffler with end plate on.
Removing the butt plug doesn't disable the spark-arrestor in the stock muffler
Cons: Stock muffler is very heavy.
<Kirk - Stock head pipe is very restrictive>
Cost: No extra cost.
 
Stock Muffler -- End Plate Removed -- Big Gun Tapered Head Pipe
Pros: Acceptable noise level.
Cons: Big Gun head pipe provides no gain in power over stock header <Kirk - when used with stock muffler>
Big Gun tapered head pipe does not fit the stock muffler.
Big Gun tapered head pipe only improves performance with Big Gun silencer.
Stock muffler is very heavy.Stock muffler is very heavy.
Cost: Big Gun head pipe = $175.00
 
Stock Muffler -- Stroker Unrestricted Downward Facing Tip -- Stroker Head Pipe
STROKER VS STOCK HEADPIPE => CLICK FOR PIC
Pros: Acceptable noise level.
Stroker oversized head pipe fits the stock KLX 300 muffler.
Stroker head pipe provides slight gains in power across the band over stock header/muffler.
Cons: Stock muffler is very heavy.
Cost: Stroker unrestricted downward facing tip = $45.95 and Stroker head pipe = $140.00
 
Four Stroke Works -- Head Pipe, Muffler and Quiet Tip
FSW EXHAUST SYSTEM => CLICK FOR PIC
Pros: Under 90dB noise level.
Much lighter than stock muffler.
Significant power gains across rpm band over stock system
Cons: Muffler not stamped to indicate USFS Approval of spark arrestor
But the FSW spark arrestor is approved... CLICK FOR PROOF
Cost: Head Pipe = $154.99
Muffler/Spark Arrestor = $299.99
Quiet Tip $64.99 but free with muffler
 
Supertrapp Internal Disc Muffler -- Quiet Core -- Stroker Head Pipe
Pros: Acceptable noise level.
Supertrapp muffler with quiet core is quieter than stock muffler with end plate removed.
Supertrapp muffler is about six pounds lighter than stock.
Cons: Supertrapp muffler does not provide any noticeable difference in power over the stock muffler/Stroker downward tip/Stroker head pipe combination.
Cost: Supertrapp internal disc muffler = $179.99
Stroker head pipe = $140.00
 
Supertrapp Internal Disc Muffler -- Quiet Core -- White Brothers Head Pipe
Pros: Acceptable noise level.
Supertrapp muffler with quiet core is quieter than stock muffler with end plate removed.
Supertrapp muffler is about six pounds lighter than stock.
White Brothers head pipe provides better power across the band over stock head pipe.
Cons: White Brothers head pipe does not fit properly with the Supertrapp muffler.
Cost: Supertrapp internal disc muffler = $179.99
White Brothers head pipe = $123.99
 
White Brothers E-Series Muffler -- Stock Head Pipe
Pros: Acceptable noise level.
White Bros. E-Series muffler is quieter than stock muffler without the end plate.
White Bros. E-Series muffler is about one pound lighter than the stock muffler.
Cons: White Bros. E-Series muffler provides no power gain over stock muffler with end plate removed.
<Kirk - Stock head pipe is very restrictive>
Cost: White Bros. E-Series muffler = $275.99
 
White Brothers E-Series Muffler -- Stroker Head Pipe
Pros: Acceptable noise level.
White Bros. E-Series muffler is quieter than stock muffler without the end plate.
White Bros. E-Series muffler is about one pound lighter than the stock muffler.
Some high end power gain over White Bros. E-Series muffler with stock head pipe.
Cons: Little low end power gain over White Bros. E-Series muffler with stock head pipe.
Cost: White Brothers E-Series muffler = $275.99
Stroker head pipe = $140.00
 
FMF Megamax Muffler -- Stroker Head Pipe
Pros: Acceptable noise level.
FMF Megamax muffler is four-way tunable: open competition, quiet core, disc system, or quiet core and disc system together for quietest level.
FMF Megamax muffler is significantly lighter than stock muffler.
FMF Megamax muffler provides slight mid and high end power gain over stock muffler.
Cons: FMF Megamax muffler provides little low end power gain over stock muffler.
Cost: FMF Megamax muffler = $237.99
Stroker head pipe = $140.00
 
Stroker SX1 Straight Through Muffler -- Stroker Head Pipe
Pros: Stroker SX1 muffler is about five pounds lighter than the stock muffler.
Stroker SX1 muffler and Stroker head pipe fit flawlessly.
Significant power gain in low end and mid range.
Cons: Stroker SX1 muffler provides little high end power gain.
Stroker SX1 straight through muffler is considerably louder than the Supertrapp muffler or the stock muffler with the end plate removed.
Cost: Stroker SX1 straight through muffler = $200.00
Stroker head pipe = $140.00
 
Pro Circuit Disc Muffler -- Thumper Racing Head Pipe (which is exactly like Stroker Head Pipe)
Pros: Quiet noise level.
Pro Circuit disc muffler is significantly lighter than stock.
Pro Circuit disc muffler with Thumper header provides smooth power gains across the band.
Pro Circuit disc muffler with Thumper header possibly smoother and more responsive than Stroker SX1 muffler with Stroker header.
Cons: Pro Circuit disc muffler is slightly heavier than Stroker SX1 muffler or Big Gun muffler.
Cost: Pro Circuit disc muffler = $184.99
Stroker head pipe = $140.00 (Thumper Racing web site is down so their price n/a)
 
Big Gun Silencer -- Big Gun Head Pipe
Pros: Big Gun silencer is very light.
Big Gun silencer provides very significant power gains consistently across the band.
Cons: Big Gun silencer is extremely loud with either the Big Gun quiet core or race core.
Cost: Big Gun silencer and Big Gun head pipe combination = $370.95


So what does all of this boil down to?