Instructions for installing the BDSB Power End Cap on the 2016-2018 SXF / XCF / FX / FC and All 2017-2020 KTM / Husky 250s through 501 4 strokes.
The bolts that hold the stock end cap on are easier to get off if you remove the muffler first. Especially on the Husky. They are a torx bolt head, size T25.
You will probably notice that the holes in the muffler can are ovaled out and don’t line up too well with the muffler cap. The Huskys are worse than the KTM’s it seems. They aren’t all this way but it seems these mufflers were just assembled by really mad teenagers that cared about nothing.
First of all, congratulations on making an intelligent decision with this purchase. This kit allows you to use or not use a spark arestor and also to use or not use the quite insert. It’s the only muffler option on the market to allow you to remove one without affecting the other.
After the bolts are out, you can beat the end cap off easier if you put the muffler back on the bike. Yes, I am using a chisel and a big hammer to bang it off.
The KTM’s come off pretty easy, but the Husky’s will probably need some good smacks. Some really good smacks so don’t be a sissy here. If the bolts are out there is nothing holding it in except friction and the fact that the mad teenager who put it together smashed part of the cap into the core and it’s stuck.
It will come out though. You’ll need to beat it on the top and bottom side if you have a Husky FE. The FX and FC models come out pretty easy.
When the end cap comes off, there is some packing material that sticks out of the end. You will want to remove it by cutting it off. It cuts off pretty easy with a sharp razor blade. Cut so that it’s about flush with the end of the muffler can.
You can see that the bottom of the core on the FE muffler is all banged up. Seems like a lot of them are that way from bad assembly practices. You may have to grab the pliers and straighten it out or make it round again before you install the new end cap.
Tap the new end cap in. It goes in a lot easier than the old one came out. You can see here how far off the can’s screw holes are.
They are all ovaled out from the stock cap. Ours lines up better with most cans, but if you have to open up the holes a bit then that’s what you have to do. Installing one screw usually pulls it more in line.
Quiet Insert Option
If you choose to use the quiet insert then just maybe put a little lube on the O-ring and slide in the end. The flat cut on the insert lines up with where you put the securing bolt. I’ve never found they need to be loctited.
Using the insert will help mellow out the bottom end hit on some bikes so it’s another tuning tool you can use to increase tractability.