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Exhuast to get some bottom hit

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Hello mates,

I know there might have been other topics with this question, but please, forgive me for creating another one. I just get some free time right now at 11 p.m.

I would like to add some bottom hit for my CRF250R 14' which exhaust system will provide it in the best way? Akrapovic, Yoshimura, FMF? Or maybe just slipons will do the job?
(I don't want to change cam shaft so that's not an option).
 

Thank you in advance!

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I don't think an exhaust / slip-on would provide what you are looking for.

By design, 4-stroke 250 MX'ers are rev happy engines with not much bottom end torque.

 

Even a 'de-tuned' and somewhat torquier CRF250X isn't that much stronger on the bottom,

and it has a specific smaller diameter headpipe, smallish carb, shorter lift/duration camshaft all suited for torque.

 

Perhaps a small chance in final drive ratio to better suit your type of usage, say adding a 1-2 teeth larger rear sprocket.

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I actually have added 1 teeth on the rear. 2015 CRF250 of my 2 friends on Akrapovic and FMF seem a bit stronger. But 15 has diffrent maps I guess. I have rode 2015 yzf, also you can feel the hit as you open the throttle.

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Not familiar with EFI engine but maybe yours requires a TPS recalibration.

 

Also, perhaps what you describe as a 'low end hit' is actually more midrange,

where an exhaust change could make a difference. 

Edited by mlatour

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(I don't want to change cam shaft so that's not an option).

Thank you in advance!

 

That's a very narrow minded attitude.

In reality, a cam change will be cheaper and have a greater effect than any exhaust system. Also you need to realize you already the 250F with the most bottom end power. Top end power was the priority for the pipe builders

Sent from my XT1650 using ThumperTalk mobile app

 

 

 

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if you put any slip-on, that by nature will reduce the bottom end hit (as it provided less back pressure). Sprocket as you mentioned is the most cost effective way. After that its a new cam and a remapping. 

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