$5 Exhaust Baffle

I did a modification to my stock WR muffler that worked well with WR or YZ valve timing. Here's what I did for a cost of $5.00:

1. Buy an automotive 1 3/4"-90 degree exhaust bend. The size is important; it fits perfectly over a sleeve inside the end cap.

2. With the muffler and end cap on the bike, slip the female end into the muffler end cap until it stops, angling the bend down.

3. Through the original insert screw hole in the end cap, drill a small hole into the extension Install a short self tapping sheet metal screw.

4. Using a hacksaw, cut off the new extension to suit your preference of down angle. Cut square to the pipe centerline at the cutting plane. Debur the cut with a file and emery paper. My turndown extended about 3" from the end cap.

5. Seal the extension outer diameter to the muffler cap with black silicone.

6. Raddle-can paint the extension and sealer black. Not required to be heat rated.

This install looked good and did the following for my bike:

A. Provided water protection to the upturned stock cap opening.

B. Significantly lowered the sound level at low throttle.

C. Preserved all the power characteristics of the open WR end cap. This is true for all the "dial in" combinations discussed in this forum.

D. Leaves the spark arrester screen in place.

Any chance you have a pic of this?

Is the 1-3/4" measurement i.d. or o.d.?

Tried one on my bike this weekend. I just asked a muffler shop for 1 3/4". They didn't have too broad a selection. I offered $5 and the guy though he was making out. It took less than five minutes to try it out, so for 5 bucks, what the heck? It fit well and I didn't bother to JB weld it in, so it fell off after 1/2 mile.

It was significantly quieter on idle. When gased, it got loud again. There wasn't any noticable loss in power. The unit still flows the same amount - just pointed straight down. For our crew of four to six WR's, it would make quite a differnce when we stop to talk.


A downside is that KerryT quickly said "It looks like a 'L?mp D?ck!' (you insert the i's) At my age, I have to worry about that image :)


I know what you mean about image! That's why I included #4 in the procedure: cut off the extension (baffle to some) with a hacksaw to suit your preference for the amount of turn down you want. My preference was to not have it "look like a 'l?mp d?ck'! So the install only needs to extend 3" from the cap for those vain types, like me.

No JB Weld is needed! #3 refers to using a sheet metal screw, and #5 refers to silicone. I used this install for 6 months with more than a few direct impacts from riding Arizona rocky mountain trails: not one failure. The silicone is just to seal it off and provide a nice joint to paint for appearance. And it is easily removed if needed. The sheet metal screw is necessary! Don't leave home without it!

Flyin Bryan,

The 90 degree bend you want is for 1 3/4" OD automotive exhaust pipe. It will have a male and female end. The female end just fits inside the stock muffler cap.


I'll take a digital picture of it tomorrow, then post it-if I can figure out how. It will have to be an off-machine pic. of the assembled pipe, muffler, and extension.

I emailed a picture of the extension to ThumperTalk today. Don't know how it gets posted on the forum!

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