A little back story first

On the hunt for a new exhaust system I had surprisingly found FMF will not ship me there exhaust system for my klx 250s to California as my bike is not a dirt bike, or race bike since it has the dual sport ability

Seems like every vendor drop ships directly from FMF, so they know where the exhausts go and for what bike. Rumor was from one vendor they wouldnt even sell the powerbomb header either, although I did not try to get that since it may only fit FMF mufflers, as you will see below

So im totally out of luck with that brand

Giving up the quietest aftermarket exhaust I was on the hunt for anything to get shipped to CA

Thats where I found the DG O series from an ebay seller located in Ca. They shipped next day and it arrived a day later I believe. I also purchased a silencer insert which they installed before shipping Kawasaki KLX 250S items in klx 250s store on eBay!


Now onto the Chinese PowerBomb header from ebay New s s Bomb Exhaust Head Header Pipe 2006 13 Kawasaki KLX250S KLX250SF KLX250 | eBay

I had read in another thread I did recently about these clone headers may not fit to the exhaust so I wanted to contact the sellers and ask for specs
I noticed 2 sellers ended up being the same person, and the other ones I saw were more money shipped
So I went with the cheapest one first to get any info I could

I think the seller is in china, and they could not give me any dimensions
but the product did ship from Florida but for free shipping too like a week to receive way longer then I was expecting for fed ex

Anyways the header I got does fit with a few mods

First off the header flange holes were a hair small, so one size larger with a step drill bit solved that
I think for most people that work on bikes this is a simple fix

The end pipe that slips into the muffler was a touch too large when I fit it into the stock, and aftermarket exhaust pipes
This was fine, just like the stock one is larger too
At least it wasnt smaller

Since it had no slots cut into it, I assume its meant to just slip over the stock exhasut. Since it looks like the sale ad seems to mention it working on the stock exhaust, not aftermarket ones

I even took out the stock exhaust gasket, but that was too thick to fit into the new header when using the pipe

So what I did was cut 4 slots into the new header, so I can use the clamp
again I dont think this is too hard for most to do but I wasnt expecting to do this
At this point I could no longer return it as they would know I had changed it

I also split the stock gasket in half, and cut a little smaller and was able to slip in everything and tighten down the clamp
And of course if I had to go back to stock header I would now be without a good gasket, so im set on making this one work

Checked for leaks front and at the clamp, none so thats good

On cold startup I immediately noticed a quieter exhaust note, using the DG muffler and silencer tip
Riding around its a touch quieter, and freeway speeds it is too
Thats good news freeway was a little loud in my helmet with the stock header

This makes it seem close to what the FMF PowerBomb header claims, at least how it can lower the sound level a little more

As for anymore or less gains hard to say
bike sounds slightly quieter, and so far nothing bad enough to think its loosing any power
But I have no accurate way to test that

Im more concerned about the noise level anyways, as doing all these mods really gave the bike alot more power so im really happy with how everything turned out

I had put 6000 miles on a bone stock bike, so these last few mods really woke it up


Here is what I ended up with, using a DB meter app on my ipad
I had done before and after videos all along doing these mods

So all stock I had readings of
85-87 db
max out at 94



Just aftermarket muffler stock header
at idle 88-90 3 db more then stock
100db max 6db more then stock




And the whole exhaust setup, muffler and header
at idle 88-90 3 db more then stock
max 95 1 db more then stock






video comparing bone stock
to what I have now








Looks exactly like the FMF one except for the welds

 

Outstanding post.. Setting the viewer to 720p and going full screen is the way to go with your video.. Wish I'd known that cheap header would work with my DG slip-on before I went out and spent $500+ on a full FMF system.. What do you have in that exhaust now, about $270 ?

From my Dyno testing, you should pick up some HP in the upper RPM range with that bomb header. The noise mitigation is very important to a lot of us as well.

Your KLX is about the nicest looking example I've ever seen - remind me of who makes that skid plate and side protection/luggage system..

 

header $92
silencer tip $33
muffler $170
so around $300


jets $80 directly from dynojet
I think I had found a cheaper supplier but wasnt sure if it was the same brand
plus dynojet had crazy high shipping charges

 

I think the guy was called pmracks
dont remember
he used my bike to build them as he didnt have my year yet in his inventory

not sure if he ever sold the front guards I had asked for those to be made

 

What is the diameter of the header?

 

I can give an outside measurement if that helps

stock
at bend 29mm
straight run 32mm

new
at bend 34mm to bomb
after bomb 38mm

 

So the I.D. of the nipple on the DG/stock muffler is significantly smaller than the I.D. of the header it is slipping into ?

 

yes if you measure the stock one, minus gasket

the clone bomb was a hair smaller, maybe 2mm?

where the stock one is larger to make up for the thick gasket
I had to strip the gasket in half in order to have a snug fit

I didnt want to chance a leak if I didnt use the gasket, and that stock clamp
so far all worked out

I may order a couple gaskets though one for the stock incase I have to go back
and another one to split in half cleaner then the one I did today

unless someone knows another model or brand gasket thats not as thick

 

you thinking this header is a copy of the fmf
and the flange is too, thats why it wasnt a snug fit?

I was told it was to fit on the stock muffler when I was asking about the size
they made it seem like if I was using an aftermarket muffler they cant gurantee it would fit

I tried saying if the aftermarket fits my stock header, then it wont be any problem fitting this clone
but I could not get them to go into much detail
Thats why the first thing I tried this header on was my stock, just incase it didnt fit

 

After studying your photo of the DG to Bomb connection, it's obvious to me that the cheap bomb connects up to the DG far better than an actual FMF header. I had to use a whole roll of exhaust tape on the nipple of my DG before it would fit in the "bell" of the Megabomb snugly.. So you are likely getting another HP or so up high..