E-series disk questions

Three quick questions regarding an e-series s-bend shorty, although the first question is for any e-series pipe.

1.) On an E-series, do you count the sound deflector, spark arrestor or end cap as disks?

The WB manual doesn't indicate one way or the other, but I'm leaning toward, no only a blank diskd is a "disk".

2.) What have other riders found to be the optimum number of disks for the strongest bottom/mid with YZ timing? Can is matched to a WB tapered header. E-series Shorty can.

Sound output- What number of disks is a happy medium betwen sound output and power? Is there any accessories that will lower the sound w/o decreasing power? I use the 180 degree (wraps around both sides and top) sound deflector currently, but I'm looking for something even quieter is possible. Probably not, huh?

Thanks, all!

I agree with Hugh, only the disks count not the end cap.

I run 5 to 7 disks depending on elevation. I remember reading a old posts and most seem to prefer 6 to 9 disks (do a search). I tried more and found I needed to re-jet so I went back to my original configuration. I also bought the quiet core insert which reduced some of the dbs. It's still fairly loud, even with the insert and the small disk quantity...but my old Yosh was much louder.

I have found that the factory packing sucks. After 3 or 4 rides my original packing was almost gone. The poor guy behind me was getting peppered w/ shreading fiberglass.

hope this helps

What about......

The end caps. When I bought mine (99) I wasn't given a choice (I have the big oval and run the blank + 12 discs). I see in this months Dirt Rider a pic of an E-Series with what looks like a stock YZ End cap.

Does that replace the oval end cap. If you use the YZ style end cap, do you NOT use the Blank disc?


I currently run seven disks. It is quieter than my friends 02wr426 with stock pipe.


I had the E series. I ran 10 disks and it was loud but produced great power. I then purchased the "quiet core" and ran 6 disks. That got the decible level down to 101. With the 10 disks it was 106 to 107 db's. The quiet core insert helped the sound but certainly diminished the power. For trails this was ok, but on an mx track it really lacked the "bite" that WR's are known for. I eventually put a FMF power bomb head pipe on with the E series and that helped a bit, but wasn't worth the cost in the end. I than put on the Big Gun SDS system which was supposed to give some good "pop" and quiet noise levels. That was a bunch of B.S. The noise was the same was W.B. As has been discussed so many times before, sound vs quiet, it is difficult to find that happy medium. I eventually ended up with the KTM 400 exc and that gave me the balance I was looking for. The WR was a great for me at the time, and still is an awesome bike. You would think that if KTM can put together a bike that produces great power and low noise for a 4 stroke that Yamaha could do the same. Good luck in the quest for power and quiet.

Mike in Roseville

You are right about the number of discs. Don't count the end pieces or all that other stuff.

Most pepole here find that more discs = more top end, less discs = more bottom. I run 12 and find it real fun on tracks but yes it is loud and wonder what that can do to our sport. I will not put such a loud pipe on the next bike I get and I will remove a few next season. I think 7 or 8 will suffice.( I sold the original pipe on the WR side ) BTW I run the high-boy header for ease of oil change. It mirrors the stock pipe, adds just a little more everywhere.

[ February 07, 2002: Message edited by: Hugh LePage ]

Thanks, all.

I will try 9 disks and go down from there. I was using 12, and it's just too loud. Loved the power, but absolutely no stealth. I'mwilling to drop a pony or two to make less noise.

Bill, I think the turn-down tip is not compatible with the blank disk, which is really the spark arrestor! The turn down should be quieter by nature, but don't want to loose the SA capability (it's required in a few places I ride, not that anyone has checked, but I don't want to be guy starting fires!). If this isn't true, the turndown may be the ticket!

Can anyone comment if the turn-down tips work with the spark arrestor?

Interesting comment on the packing, my pipe was used and probably has the original packing. I don't see any stray fibers coming out, but probably wise to replace the packing anyway, huh?

BTW, anyone with a Ti E-series for sale?

Hmmm, someone posted to bring this to the top, but nothing shows up!

I've noticed a few other missing posts before, too!

I run 12 disks and it doesn't seem to be too loud, but maybe that is because I have the longer E-Series that looks like a bazooka hanging off the back of my bike. I don't know what the intended differences are between the two.

I do have a brand new WB quite core insert that I'll sell for $20 if you are interested

Hey Bill, I'm sure I've seen the turn down bolted on with the blank and disks. My understanding is that it is just an option for a different look. It may be a bit quieter without the blanks. You should be able to find out if you contact WB.

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