YZ400 head pipe that clears filter

I purchased a White Bros high-boy ( meaning up and over the oil filter ) header pipe. I looks great in the box but haven't put it on yet. :) White bros have documentation out there on their web site and after having done some research last fall decided on this one for a) price :D availability c ) reputation. My bike is down to the frame so it will be a few weeks ( read months up here in Montreal ) before snow melts until I can say if there is an improvment.

[This message has been edited by Hugh LePage (edited 02-08-2001).]

I had a Procircuit T4 pipe on my 99 YZ400. It was great for low and mid and had an quickly removed S/A. The bike definately felt faster to me with it. It was 0.95 lb lighter than stock (weighed it myself). It cleared the oil filter with ease. It was well made, looked great. (The WB R4 is a very similar pipe, I don't know about the header though).

Downsides the the T4:

1. LOUD!!!

2. No heat shield, though I never burnt myself.

3. Expensive ($400)

4. Interferes with some aftermarket tanks, most notably the Ty Davis Lowboy, which is why I sold it with the 400 when I got my 426.

Good Luck in your pipe search.

I can’t think of any header that won’t both clear the filter and melt your pants. Most of them are louder, but FMF and WB both make a “quiet” model silencer (Hawkins and Quiet Core??).

I’m pretty sure that FMF and WB silencers and headers are compatible with stock YZ pieces, but I know PC T4 is not. I don’t think DSP and Yosh are either.

Expect to pay over $400 for a header and silencer. Most aftermarket systems seem to steel a little off the top to boost the mid and low, so if you are rev happy you may want to try and find a stock ’01 system. They are stainless, clear filter, have a heat shield and will probably perform better than your stocker, but finding one will be difficult. The stock ’00 is another good idea, it isn’t stainless and doesn’t clear the filter, but it is significantly different than the ’99 exhaust and should also perform better.

If you don’t have a steering damper I’d buy that first :)

BTW I also have the PC T4, it was about $450 I think. A bit less scream up top, but more, longer & smoother power from bottom to upper mid. It works good for my riding, is very well made, fit perfectly, has no gasket in the midsection, is a few pounds lighter than stock and comes with a removable SA insert. You can also get two different sized end caps, but I haven’t tried one yet. It melted a hole in the LEFT leg (not sure how that happened) of my new pants so I wrapped the header with exhaust wrap (like for automotive headers). Oh yeah, one more thing, IT IS VERY VERY LOUD.

Scratch the “two pounds lighter” thing, I just read that in Dirt Bike and didn’t weigh it like Mike did.

I suppose I should READ all of the post before I open my mouth. Oops.

I'm running the WB High-boy with WB spark arrestor. My neighbors tell me it’s loud.

However, the performance is better than the stock header pipe with FMF PowerCore IV. But the FMF pipe use to puff up little circles of dust about five feet from the bike when you hit the throttle while parked. I miss that.

As for that "do you smell smoke?" problem, I've melted my right pant leg while riding, and even further while just sitting on the bike hanging out...like when you’re trying to be cool.

Then melted the left pant leg pushing the thing up into the truck.

If I could just get a hot dog to stick to the header pipe I wouldn't have to eat cold beans from a can anymore.


Could anyone give me a list of companies that make the head pipes that clear the oil filter for my 99' yz400? Also does anyone out there have one and have any opinion on it regarding sound and power differences? Does anyone know the price range on these things too? Thanks



When in doubt, GAS IT!

Dave, would like to know how many discs you are running, how this set-up affected your jetting, ( as I have identical set-up ) and what should I do to avoid burning my pants when trying to look cool. Also any suggestions as to how long I should idle the motor before roasting my lunchtime hot dogs would be appreciated.

Thank-you in advance for your help.

Remember if the women don't find you handsome at least let them find you handy!


[This message has been edited by Hugh LePage (edited 02-09-2001).]


I actually got a Noleen complete setup.

Tapered header/"silencer"(yeah right!)

It is the loudest thing i have heard on a bike for a while.

I got rid of the "Silencer" and replaced it withe the E-series and added discs (14ttl)

The silencer was burning out the packing almost every other ride and like if you put a coffee can up to the headers on a hopped up 66' Stang.

Louder than hell.

Plus it has got to be the ugliest pipe ever made.

Looks a lot like the new Pontiac Aztec SUV!!!

The header will not work with the stock silencer though.

I burned up a brand new pair of "Free-style"

type of pants last weekend and wasn't very happy bout' that! but MyThor pants that tuck in have no problems unless the bike is "Laying" on them.........LOL

The header/pipe cost me $200 cuz of cnx!!!!

I think the headers are usually about $150-200.

The oil filter is easily accessed with a header like this and that makes all the diff, in the world when you change the oil as much as I do!




ride BLUE


12 discs, 165 main, 45 pilot, 1.5 turn out, and 4th position on needle. Pump gas. California weather.

This took some time, so I'm fairly confident with it for altitudes under 3k. I also run idle a bit higher for better starts (sorry, no measurement).

This just about eliminates the off idle problem as well. If not, crank up the accel pump a notch.

I tried an open exhaust one day and it had better pull throughout the range, so perhaps a few more discs would add a bit more punch.

The hotdogs and being cool part will have to wait till a later post, (have to go buy parts)

Hope this helps.


Thanks for the info Dave!

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