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Discussion Starter #1 (Edited)
is there really a differance between the two? I plan on getting my son an aftermarket exhaust but is it really worth getting the head pipe? I know i will have to rejet and get a better air filter any way i go. thanks for any input.

by the way, i just bought him this a few weeks ago, moving him up from an xtreme 125 with a 140 manual clutch motor.

I also added some tusk nerf bars from RMATV this morning. this thing is looking good.
 

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yes...the low end torque is where the difference is. We have the FMF powerbomb on the 250 and the performance gain was noticeable, combined with muffler and carb jetting this is a nice upgrade. The expansion chambers on the FMF pipes do work, I have the FMF Megabomb on my 450 and it's night and day over stock.
 

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Discussion Starter #4
If i buy the fmf power bomb do i have to use their exhaust or can i use any one's?
 

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the pipe comes with an aluminum adapter so the stock size pipe may be used... therefore I would imagine other slip-on pipes could be used as well.
 

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I really don't like aftermarket headers. The factory header is actually more free flowing than the aftermarket ones are because it is a wider pipe, giving you more up top HP. The aftermarket headers are these little skinny things that make lots of back pressure giving you more torque, but not a big increase in overall HP.. Really depends on how you like your power. Do you wan't lots of low end power, or are you more like me and want your power up top?
 

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Discussion Starter #7
Thanks guys for the info. I really need to do more research on this. I dont really trust the manufactures claims to anything. Need more info from the actual users.

another thing to throw into the mix is if you have any head work done. just a little clean up work on the head. How much does that help?!!
 

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Not all aftermarket head pipes are skinny...If I were you I would get an FMF powerbomb head pipe, it is twice the size of the stocker

I would get exhaust and jet your carb before you start doing head work, but if you do decide to port and polish it, you will notice gains
 

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The stock pipe according to Yamaha gives you better low end torque. Aftermarket head pipes are supposed to give you better top end horsepower. I did notice a difference with my aftermarket pipe, mainly because I had to go up 1 size on the main jet for it to run right. With that said, an aftermarket headpipe only does what it's supposed to do it it's jetted corrrectly.
 

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The stock pipe according to Yamaha gives you better low end torque. Aftermarket head pipes are supposed to give you better top end horsepower. I did notice a difference with my aftermarket pipe, mainly because I had to go up 1 size on the main jet for it to run right.
I know Yamaha said they designed the silencer part of the exhaust with 3 chambers for increased torque, but I never heard any info on the header. Technically, the factory header is a very skinny pipe, but if you look at some of these aftermarket exhausts, they are much skinnier than the factory pipe for increased torque. But there are also header header pipes that are much wider than the factory ones for better flow (more top end power, less torque) such as the FMF PowerBomb... really depends on how you like your power, do you want that real 4 stroke bottom end grunt, or do you want more of a 2 stroke type of powerband.....

an aftermarket headpipe only does what it's supposed to do it it's jetted corrrectly.
This is very true....
 

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Found on Off-Road.com featured in the Raptor 250 review

"Yamaha used a extremely long and odd looking head pipe in order to deliver more low end power."

The perfect teen ATV to compete with the Blaster and 300EX
 

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when I put my FMF powerbomb on, I definately noticed more grunt and the quad almost lifted off the ground. You can stay with the stock header if you want but if you are going to race it MX and are against a guy with a powerbomb or nice full exhaust set-up, you will be introuble

If you are not sure about a headpipe then just get a nice high compression piston
 

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Discussion Starter #13
So it seems there is pro's and con's between the stock header and an aftermarket one. what i read is stock for low end and aftermarket for top end. This wont be used for racing, well maybe some flat track once in awhile. but mostly for the dunes, where we run mostly wide open.
 

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The headpipe is a fairly cheap mod, if you are taking off the air box lid, upgrading the exhaust, might as well buy the pipe. When you jet it, it will run fine.
 

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I opened up this can of worms last year when I purchased my GYTR head pipe. The thread was misspelled as "heardpipe." Combining some research and personal experience with my yfz450 I came to the conclusion that GYTR head pipe was inferior to the stock in overall performance, yes bottom end and top end. But I am not saying that all aftermarket head pipes are inferior. The side conclusion was that the stock head pipe is actually a very good head pipe. Using 2 raptor 250's, the same Lexx slip on's, and 3 different head pipes, with proper jetting we decided the differences were minimal either way. Long story short, if I started over again I would save $$ with only a slip on. I believe the stock header would even be good for big bore, porting, etc. All of this is my opinion and based on our experiences comparing 2 raptors. Many factors are involved in making horsepower so of course every motor is different.
 

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IMO you need the mods to get all the gains from huge head pipe. On one quad we have a full blown Rage 300cc motor with matching head pipe/exhaust. On the outher we have a full cp exhaust which is smaller but with matching mods (in my sig) you will get the most out of the pipe you choose. Just my .02
 

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There is an exhaust for all your needs. I would call the stock header the middle ground. i have a full DR.D system which uses a stepped header. From the flange and about 6-8 inches where it loops through the frame, the pipe is probably 1/4" diameter smaller than the rest of the header, and the rest is a little skinnier than the stock header by a hair. That exhaust has given me an amazing gain in torque and brought most of the power toward the bottom end. It pulls really hard in the mid-range. Now for more of a top-end exhaust, the CT seems really like a top end pipe. It goes straight back from the port instead of having the extra length looping through the frame before turning, and has a huge header and muffler
 
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