Get a great aftermarket exhaust sound for free – just shorten (A,B) or drill (C,D) the stock muffler.
You can do it four ways – A) without the end-cap, B) with the end-cap, C) just drill out the exhaust tip, or D) drill the plate inside the muffler using a drill extension
For the Rebel 300, this is the only way to get an aftermarket sound while keeping the stock catalytic converter.
Summary:
A)…LOUDEST [106 dB] cut the muffler off 77 to 120mm (4.7 inches) from the end (I did 84mm or 3.3 inches). Save the part you cut off.
B)… LOUDER [100 dB] remove the end-cap from the part you cut off in “A” and then re-install the end-cap on the muffler.
C)…LOUD [97 dB] EZ method. step 1) Place a 38mm (1.5 inch) holesaw over the exhaust tip and drill out the rear of the stock muffler. step 2) Using pliers, pull out the exhaust tip.
(EZ method per “harryhorton 1956” from hondarebel3forum.com)
1 1/4″, 1 3/8″, 1 1/2″ holesaws will work. Larger will be a little louder. (1 1/8″ and 1 3/4″ will NOT work)
D)…LOUD [97 dB] Using a 12 inch drill extension in the muffler outlet, drill a 1/2″ hole in the right side of the baffle plate which is mid-muffler. If not loud enough, enlarge the hole to 3/4″.
Stock exhaust is 94 dB
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A)…cut the muffler off 70 to 120mm from the end (I did 84mm). Save the part you cut off.
I believe shortening by only 84mm will give a deeper tone than shortening by 120mm.
B)…remove the end-cap from the part you cut off in “A” and then re-install the end-cap on the muffler.
The end-cap will be held on by one bolt, so you can easily remove the end-cap if you want it to be louder. Without the end cap, it is much louder than stock and sounded great. Adding the end cap reduces the loudness by 3 dB or more – it is still quite a bit louder than stock.
Cutting off 84mm reduces the muffler weight from 8.7 lbs to 6.8 lbs. (6.25 if you also remove heat shield)
Rebel 300 – Shortening the stock muffler is a great idea for the Rebel 300. It is the ONLY WAY to get an aftermarket sound while keeping the stock catalytic converter. None of the aftermarket mufflers have a cat. The mod involves removing the last 3 to 4.5 inches of the muffler. I am 95% sure the cat is in the front section of the muffler. Catalytic converters work best when at high temperature, so cats are usually located forward in the exhaust system.
Audio of my shortened Rebel 500 muffler. (cheap cellphone – video quality is terrible)
https://photos.app.goo.gl/SUqjnoki1akmQnFC7
Here is a pic and link from “Slono” from the hondarebel3forum. He cut 100mm off his muffler.
To me, the shortened muffler actually sounds louder than it sounds in this video. It is quite a bit louder than the stock muffler.
Tips
You do not need to cut clean through the muffler – just the outside shell.
If you do cut clean through the muffler, you will be cutting two small pipes – this does not matter since the two pipes are not used.
If you want, you can do the projects as two parts: 1) cut the muffler and then 2) remove the end-cap from the part you cut off and then re-install the end-cap on the muffler. The advantage of this is that you can be driving around sooner evaluating whether you like having no end-cap and then later you can take your time removing and re- installing the end-cap.
If you are not sure what length you want, I recommend 85mm. The halfway point of the rear muffler section is 77mm.
If you use the muffler without the end-cap, it would look nicer if you added a round trim ring – OD would be 120mm (4.75″) and ID would be 108mm.
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C)…EZ method – 2-step procedure per “harryhorton 1956” from hondarebel3forum.com
step 1) Place a 38mm (1.5 inch) holesaw over the exhaust tip and drill out the rear of the stock muffler. — see photo.
step 2) Using pliers, pull out the exhaust tip – see photo
Rebel 500 header pipe extension 43mm OD
The Radiant GP Shorty exhaust has a 43.2mm ID inlet to slip over 43mm OD header pipes.
If you connected a GP Shorty to a 43 mm OD to 51 mm ID reducer, then to a mid-pipe, it might improve the low-end torque of the bike compared to the GP Shorty alone.
restated – Short exhausts can reduce the torque/ performance of the bike. If you connected a Shorty muffler to a mid-pipe, it might improve the low-end torque of the bike compared to the Shorty muffler alone. But most Shorty mufflers have a 43mm inlet (not 51mm like most mufflers) so you would also need a hard-to-find 43 mm OD to 51 mm ID reducer to connect the Shorty muffler to a mid-pipe.
Question: I’m just so curious on how the black widow would sound on the 300 vs cutting out stock baffle tube. …. I would try removing the stock tube first as it is fairly easy to do. Then if you want it louder, think about getting the Black Widow, which is a great choice since it sounds great, is a quiet muffler, and lower priced than the other high end mufflers. It will be louder than the modified stock muffler because the catalytic converter is in the stock muffler. ….. I’m currently running a stock muffler with your recommended tube delete. That’s loud enough for me but the stock muffler is so ugly and heavy. I guess that’s my only option because I want to retain the cat on the 300. I feel the top end suffers with no backpressure IMHO
Rebel500 