new carb or exhaust on top of 351
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That's where the 40mm carb comes into play? 
I'll find out because mine will be here in a couple months.
This TM36 is doing so well on my 250, the additional 80cc should easily be up to a 4mm larger carb bore. Especially with an accelerator pump to counter low any inherent low speed speed lag.
Luckily the cam mod is easy to do and undo if I just take the spring off the ACR.
Someone here used Webcams and didn't notice much of an improvement-he said it'd kind of be the last thing to do after all other mods were exhausted
Supersonic nozzle
I'll find out because mine will be here in a couple months.This TM36 is doing so well on my 250, the additional 80cc should easily be up to a 4mm larger carb bore. Especially with an accelerator pump to counter low any inherent low speed speed lag.
Luckily the cam mod is easy to do and undo if I just take the spring off the ACR.
Someone here used Webcams and didn't notice much of an improvement-he said it'd kind of be the last thing to do after all other mods were exhausted
Supersonic nozzle
wildcard, I agree it's hard to believe a smaller header pipe can give more performance over a better breathing header for a performance engine. If you were to have head work, very aggressive cams, then I would tend to agree that a header is needed to maximize the power. However, if you just do the big bore kit, the valves are still the same size, the cams are the same grind, and some people (sadly me even though I want one) can't justify the cost of a header($250?) compared to a pumper carb(tm36 $300) since the power gained from the header will be minimal if any at all on just a big bore kit alone.
Last edited by RockabillSlapMatt; Mar 2, 2014 at 12:19 AM.
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wildcard, I agree it's hard to believe a smaller header pipe can give more performance over a better breathing header for a performance engine. If you were to have head work, very aggressive cams, then I would tend to agree that a header is needed to maximize the power. However, if you just do the big bore kit, the valves are still the same size, the cams are the same grind, and some people (sadly me even though I want one) can't justify the cost of a header($250?) compared to a pumper carb(tm36 $300) since the power gained from the header will be minimal if any at all on just a big bore kit alone.
A header is about $150 (115 if you go with a knock off).
Each his own like I said.
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only $150? I stand corrected, I'd try it for $150 bucks.
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Hey Matt, looks like the mega bomb can be had for as little as $219 w free shipping.
FMF MEGABOMB HEADER SS KAWASAKI KLX250S 2012-2013 - Discount Moto Direct
FMF MEGABOMB HEADER SS KAWASAKI KLX250S 2012-2013 - Discount Moto Direct
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Hey Matt, looks like the mega bomb can be had for as little as $219 w free shipping.
FMF MEGABOMB HEADER SS KAWASAKI KLX250S 2012-2013 - Discount Moto Direct
FMF MEGABOMB HEADER SS KAWASAKI KLX250S 2012-2013 - Discount Moto Direct
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Straight from FMF website....
Can I run one of your headers with my stock muffler?
Our headers, whether it be the PowerBomb or the MegaBomb, are fitted to match an FMF series muffler. We do not recommend or guarantee you try to match it to a stock muffler..
Can I run one of your headers with my stock muffler?
Our headers, whether it be the PowerBomb or the MegaBomb, are fitted to match an FMF series muffler. We do not recommend or guarantee you try to match it to a stock muffler..
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More from FMF - Rider Support - FAQ - FMF Racing
How much power will I gain using FMF products and will I notice a difference?
If your definition of power gains is, substantially increasing horsepower & torque, rate of acceleration, and the important fun factor, then yes you will gain lots.
Generally you'll see a 5%-20% increase over stock depending on your application, but like jetting there are many variables to contend with. Don doesn't put in countless hours of R&D time and lost sleep into a product to not have it perform like the way he feels it should.
We've been around long enough, that you can trust that any time you install an FMF exhaust product, you will definitely " FEEL THE POWER ".
How much power will I gain using FMF products and will I notice a difference?
If your definition of power gains is, substantially increasing horsepower & torque, rate of acceleration, and the important fun factor, then yes you will gain lots.
Generally you'll see a 5%-20% increase over stock depending on your application, but like jetting there are many variables to contend with. Don doesn't put in countless hours of R&D time and lost sleep into a product to not have it perform like the way he feels it should.
We've been around long enough, that you can trust that any time you install an FMF exhaust product, you will definitely " FEEL THE POWER ".
