Jump to content
Sign in to follow this  

when do pack a muffler

Recommended Posts

i got a 2010 yz250f with 64.2 hours on the bike and muffler when should i repack it:banana:

Share this post


Link to post
Share on other sites

Its the same amount of packing, you replace it all. Better performance if done regularly

Share this post


Link to post
Share on other sites

Can someone please explain WHY it gives better performance? If that is indeed true.

I could understand if the exhaust gas had to pass through the packing in order to exit the pipe, but the silencers I've seen all have a straight perforated pipe surrounded by packing. I thought the packing was just to absorb the sound vibrations. It seems like there would be no additional flow restriction if the packing was clogged, since it is essentially a dead-end path through the packing anyhow - just an increase in sound.

Share this post


Link to post
Share on other sites

i have never repacked my mufflers at the rate some have stated above, not saying im right though. :lol: Do you see any discoloration on the can surface? (if so your risking blowing right through the can and needing to buy a new one). you can sometimes remove the can and shake it back and forth. It usually begins to blow out closest to the mid piple.. if it has blown out significantly, the pack will shift back and forth in the can and you will feel/hear it.

yes the bike runs better with full tight packing. I don't know why, just trust us it does.. LOL

Share this post


Link to post
Share on other sites

Pipes and silencers are tuned perfectly by altering their volume. If a silencer is clogged with carbon, this can change the available diameter of exhaust gases to take up, potentially affecting performance. Dents do the same thing. Maybe my teacher was wrong tho, who knows.

Share this post


Link to post
Share on other sites

Allowing the packing in your silencer to deteriorate certainly does impact engine performance. The packing absorbs the sonic pulses traveling through the silencer. Oil-saturated or burned out (or missing) packing will allow the undamped sonic pulses to reverberate inside the silencer, changing the smooth, orderly laminar flow of exhaust gasses into a disorderly turbulent flow with chaotic wave propagation and cancellation. The turbulence produces resistance to flow, and the disturbed and random sonic waves alters the wave tuning of the exhaust system. The effects increase as the volume and velocity of exhaust gasses increases. The result is a reduction of peak power and over-rev.

Keeping fresh packing in your silencer not only makes your bike quieter, it makes it run better. Even if noise isn't an incentive for you to maintain your silencer (it certainly should be), the performance aspect should be.

Modern MX bikes make so much power, the average rider won't notice the subtle loss of performance. Hell, the average rider doesn't even notice the loss of performance that results from a worn-out top-end, at least until other symptoms also appear. But the degradation of performance is real, and measurable.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×