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Just pulled the complete exhaust off my 2016 RM. I gutted the cat and fabbed a diverter for the cat chamber to allow more flow through the left muffler. I brought the cat assy to my welder for him to close everything up.

In the mean time, I decided to look in the mufflers and noticed that there was 1 plug in each about 12" in from the inlet side. Each one was bent and partially knocked open by someone before I got the bike so I completely removed them.

My question. Is there only 1 plug in each muffler in stock condition or were there more? I have noticed that some HD stock mufflers have only 1 while some have had 2.

I am asking because before I started this work, I talked to the people at Fuelmoto about a PV3 and they told me that removing the plugs would cause torque loss in low to mid range rpms.

Thanks
 

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One plug. If you look along the insides of the pipes, you will see the stock baffles. The plugs diverted the exhaust through the baffles. Removing the plugs is a common modification.
 
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Just pulled the complete exhaust off my 2016 RM. I gutted the cat and fabbed a diverter for the cat chamber to allow more flow through the left muffler. I brought the cat assy to my welder for him to close everything up.

In the mean time, I decided to look in the mufflers and noticed that there was 1 plug in each about 12" in from the inlet side. Each one was bent and partially knocked open by someone before I got the bike so I completely removed them.

My question. Is there only 1 plug in each muffler in stock condition or were there more? I have noticed that some HD stock mufflers have only 1 while some have had 2.

I am asking because before I started this work, I talked to the people at Fuelmoto about a PV3 and they told me that removing the plugs would cause torque loss in low to mid range rpms.

Thanks
Fuelmoto is correct. A lot of engineering goes into engine development, including exhaust. There’s lots of science behind exhaust technology, so knocking out a part is going to upset that equilibrium. Most knock out plugs hoping for a different sound, while sacrificing performance.
 

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I didn't notice any change in performance after I knocked out the plugs, I also drilled 5 quarter inch holes around the inside, back of the pipes. I don't like loud and this gave me what I wanted. I have a PVCX and I LOVE the sound, throttle response, and speed.
 

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I am asking because before I started this work, I talked to the people at Fuelmoto about a PV3 and they told me that removing the plugs would cause torque loss in low to mid range rpms.

Thanks
This is NOT the case as per Fuel Moto published dyno charts, as well as our charts/data. In fact, punched stock slipons perform better than most all aftermarket slipons for higher performance builds/mod combos. See this for yourself on the FM dyno web site ("modified stock" is punched plugs)..

On the other hand, your mods inside the cat chamber certainly could - and probably will - cost you power. The stock system is actually more of a 2-1 design. The left side was not designed to flow more than the as-designed volumes. See the stock internals as well as the flattened x-over pipe to prove this to yourself. The system is tuned with this minimal flow going into the left side and changing the flow characteristics will "untune" the entire system.

We know that reducing gas velocity, past the collector, with large baffles (over 2") in aftermarket slipons DO cause significant TRQ loss.
 
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