Not being an exaust expert and not needing a performance boost, is it possible to modify the stock exaust to replace that horrible stock sound. (CBR250)

Hey scorpio, did you get one then? Didn't need a test ride?

This can be had for 5900 baht

http://www.ninja250f...26&topic=3395.0

Usual stock mods involve cutting the baffles out and running a straight tube about 0.75". the stock exhaust has chambered plenums, the first chamber kills the initial report of the exhaust.

The new tube can either be a pipe with holes drilled out or a piece of perforated metal is rolled. In both cases notches are flapped into the tube to add backpressure.

Huh? ...'notches are flapped' ? - imagine the tube is cardboard and you push into it with your finger, your finger will push the material through making a little flap. The location of each or each set of flaps determines the particular rpm range where it will have an effect.

If the new tube is too big you will lose exhaust velocity and subsequently power. Although there are people who always think bigger is better.

Hey scorpio, did you get one then? Didn't need a test ride?

This can be had for 5900 baht

[/quoteNot yet, but it is on a short list. My little CBR150 allows me to take my time. Land and house first up now. I was just curious since it is such a horrible sound that "some smart one" would find a solution. Your muffler would be a good option as well.:jap:

Usual stock mods involve cutting the baffles out and running a straight tube about 0.75". the stock exhaust has chambered plenums, the first chamber kills the initial report of the exhaust.

The new tube can either be a pipe with holes drilled out or a piece of perforated metal is rolled. In both cases notches are flapped into the tube to add backpressure.

Huh? ...'notches are flapped' ? - imagine the tube is cardboard and you push into it with your finger, your finger will push the material through making a little flap. The location of each or each set of flaps determines the particular rpm range where it will have an effect.

If the new tube is too big you will lose exhaust velocity and subsequently power. Although there are people who always think bigger is better.

Thank You :jap:

OP. Take out the air filter. That will change the sound of your bike.

Tried that on a cbr 150 and almost went deaf !

Ok this guy goes step by step on how to build and modify your exhaust.

Well maybe how not to but you can be the judge

How to build your own exhaust

Ok this guy goes step by step on how to build and modify your exhaust.

Well maybe how not to but you can be the judge

How to build your own exhaust

Funny, I posted the same link earlier

Much cheaper to get an aftermarket exhaust.. In as much as IF the BIB are doing a crackdown you can put the original back on BUT if you have mutilated it you can't.