Muffler repack frequency

[Gearbox Paul]

The 250R I purchased this past summer came with a Yoshimura TRD slip on exhaust installed (stainless can with carbon fiber end cap). I'm the 4th owner of the bike and I have no clue how long the exhaust has been installed on the bike, either in years or in mileage. Nor do I know if it has ever been repacked. Considering how neglected the bike was, and how clueless the previous owner was on the maintenance history of the bike, I have to assume it has never been repacked. The bike has 13000 miles on it.

Yoshimura recommends repacking every 7000-10000 miles. Looking at the their how-to video, they mention that a pneumatic rivet tool must be used, which I don't have. I don't know why a hand rivet tool would not work, perhaps because the stainless steel rivets they supply are excessively hard. Anyhow, the repacking process seems doable but looks like a pain in the rear end.

I talked to a Yoshi rep and asked him what are the signs/symptoms that the packing needs to be replaced. He said that the can will sound hollow when tapped on the side if the packing has overly compacted. The exhaust sound and tone will change as well - it will get louder. A minor loss in power. Lastly, if the packing is overly compacted or has failed, the can will run too hot and start to discolor.

As far as I can tell, I don't have any of the above symptoms. In the absence of any maintenance history, the safe thing to do is to repack the muffler. But I'm trying to convince myself that it can wait, and doesn't need to get done right away - maybe never. Besides, being in Canada, shipping the repack kit up to me is quite pricey. I know Yoshi offers repacking service in their shop but sending my exhaust can down to them through customs and back does not appeal to me at all.

I'm reaching out to find out your experience with running packed exhausts. Is it really necessary to repack these every 7000-10000 miles. I don't care if it gets a noisier (to a point), I don't care about a minor loss in performance, but I don't want to damage the exhaust.

[DannoXYZ]

Go ahead and put it off indefinitely.

With slip-on muffler, there's no performance gains, so don't worry if muffler's quiet or starting to get loud.

You can also DIY and not have to use exact Yoshimura repack kit. I repacked muffler on my CBR600RR with titanium exhaust and CF muffler by using generic fibreglass mat. It's packed & woven mesh like felt. So it won't get blown out like fluffy insulation-type fibreglass. I also had no issues with aluminium rivets installed by heavy-duty hand-riveter.

I did this repacking when I got CBR because I didn't know history and I wanted to be sure not to get meatballed at Laguna Seca. I also installed the noise-insert as well. These measures really quieted down exhaust compared to when I first got bike.

Ali - fibreglass packing mat
Harbor Freight - heavy-duty riveter

[Triple Jim]

Depending on what the silencer is made of and how secure you want things to be, you also have the option of stainless steel pop rivets.

[BoBO]

CBR looks good!

[Gearbox Paul]

Originally Posted by DannoXYZ

Go ahead and put it off indefinitely.

With slip-on muffler, there's no performance gains, so don't worry if muffler's quiet or starting to get loud.

You can also DIY and not have to use exact Yoshimura repack kit. I repacked muffler on my CBR600RR with titanium exhaust and CF muffler by using generic fibreglass mat. It's packed & woven mesh like felt. So it won't get blown out like fluffy insulation-type fibreglass. I also had no issues with aluminium rivets installed by heavy-duty hand-riveter.

I did this repacking when I got CBR because I didn't know history and I wanted to be sure not to get meatballed at Laguna Seca. I also installed the noise-insert as well. These measures really quieted down exhaust compared to when I first got bike.

Ali - fibreglass packing mat
Harbor Freight - heavy-duty riveter

Thanks Danno. That's what I was hoping to hear.