I installed my full Yoshi system a few weeks ago and had the stock muffler sitting on my work bench. So last weekend I looked at it and wondered how easy it would be to de-core it. I mean it is a great looking muffler, much better than previous gen ones. So I took out my hacksaw and got to work. Here are the results. Next step would be to weld in a perforated 2" pipe, wrap with fiberglass and weld it all back together again. I will keep you posted, waiting for the perforated pipe to show up at the moment. Not shown is the fiberglass wrap, nasty stuff went straight into the trash.

http://i941.photobucket.com/albums/ad258/rassieva/300%20Ninja/20130813_183939.jpg (http://s941.photobucket.com/user/rassieva/media/300%20Ninja/20130813_183939.jpg.html)
http://i941.photobucket.com/albums/ad258/rassieva/300%20Ninja/20130813_183954.jpg (http://s941.photobucket.com/user/rassieva/media/300%20Ninja/20130813_183954.jpg.html)
http://i941.photobucket.com/albums/ad258/rassieva/300%20Ninja/20130813_184005.jpg (http://s941.photobucket.com/user/rassieva/media/300%20Ninja/20130813_184005.jpg.html)

This might be a noob question, but what is the purpose of doing that?

Also, didn't you try removing the catalytic converter while you're at it?

This might be a noob question, but what is the purpose of doing that?

Also, didn't you try removing the catalytic converter while you're at it?

To make it louder if you did this and weld the ends back on you have a slip on for not much invested.

Awesome lol, hope it works! I want a louder exhaust but that has to wait... I've spent so much lately.

Yes, yes, MSF advertisement... I remember that there are deaf people. Still makes me feel safer!

This might be a noob question, but what is the purpose of doing that?

Also, didn't you try removing the catalytic converter while you're at it?

One step at a time...the catalytic converter is in the header pipes. Removing it has been done before so not really a challenge.

As for why I would remove the guts from the muffler and add a straight through perforated pipe that flows more air....cheap performance I guess and I was bored and have no projects to work on at the moment.

:werd:

Rassie, keep us updated on your project. I have a 300 canister and if it turns out to be a good modification then i'm game. the 300 canister is going on my '09 250. looks so much better than the silver one.

:popcorn:
I like what you have done here, shame my welder is in NC, maybe I can find sir welds a lot down here

i cant seem to weld anything with my 1960s licoln electric Arc welder, not to mention as soon as i try to practice the misses knows cuz it damn near dims the whole blocks lights.

i cant seem to weld anything with my 1960s licoln electric Arc welder, not to mention as soon as i try to practice the misses knows cuz it damn near dims the whole blocks lights.

I usually use oxy, or my mig... Whoo, I ain't had my gear running in 6 years though, played a bit with the army toys through the years, dang I miss the engineers

I usually use oxy, or my mig... Whoo, I ain't had my gear running in 6 years though, played a bit with the army toys through the years, dang I miss the engineers

yeah arc welding is my worst enemy, gimme a mig or tig and i can weld on aluminum... gimme an arc, and ill blow a hole in what ever you need me to fix XD.

I know some guys that throw arcs with arc welders and use coat hangers like they were welding oxy... Never could do it the way they did. One of em even welded aluminum with durn arc welders... Those guys are pros!! Geniuses!!! I doubt I callus do it to save my life, may practice up an get it one day.

I know some guys that throw arcs with arc welders and use coat hangers like they were welding oxy... Never could do it the way they did. One of em even welded aluminum with durn arc welders... Those guys are pros!! Geniuses!!! I doubt I callus do it to save my life, may practice up an get it one day.

u ever in nashville u can prac on my arc welder, i have about 500 rods of different sizes cuz it was my grandpas and he was a busch league racer back in the 70s-80s, so 75% of my tools where from him. he passed when i was 5, he was an amazing man!

my mexican side grandpa can arc weld on aluminum as if he was doing something as simple as putting a line of toothpaste on a brush. every time i ask him tips he says "mira, practice and when you learn ill help you" hes the kind of man that says 5 words a day and they are always gold lol.
Rassie any more progress?

That's good stuff!!! All I know is ya strike an arc between the pieces and get your rod into the place ya want welded, as of yet I haven't got it right... Always blow through, get the arc to close, or just in general don't get the job done trying to do such things... Yea my papaw would hand me any tool or equipment to use and say leave this alone an practice on some crap over there... Some things I learned, some things I helped tote to the scrap dealer hahaha

any update??
I am impatiently waiting!!! lol

any update??
I am impatiently waiting!!! lol

Yes, sorry, work is crazy right now, we are heading for year end (Nov) so will probably only get to it after that. But it is lying on my bench tempting me.

This temptation is not helped much by the Aprilia RS250 project that is parked next to it...:D

Yes, yes, MSF advertisement... I remember that there are deaf people. Still makes me feel safer!

and blind it seems too :mad:

that looks easy enough to do.

Your having way to much fun man

Stop working so much and finish this project!!!

Actually I did, but did not work on the exhaust. Working on a ZX6R front end conversion for my 300. I am tired of the front end chatter. Will post progress and details later this week. Have to download the pictures first.

I may do the exhaust this coming weekend. Very little work left, basically just the welding.

I'm looking to do the same thing. Just waiting on your results

I'm looking to do the same thing. Just waiting on your results

Why wait? Just do it!

Haha. Time for one reason. I'm sure it will sound fine but I was trying to wait to see how it turns out first. I was going t try it on my 250 can first. I currently have the stock 300 can on my '09.

Rassie, can you get a picture of the exhaust baffle?

Rassie, can you get a picture of the exhaust baffle?

It is the nasty looking brown thing to the right of the last picture I posted. It was wrapped in fiberglass.

So finally I got around to the de-coring of the stock 300 muffler. It is now official, can be done. Nice clean straight through stock exhaust. Free (almost) power to the people (those who do not have 10 thumbs and know how to weld).

Have not tried it yet. But will probably end up swapping out the Yoshi pipe for this one at some point when I have nothing better to do (read 2055) :D

Pictures attached.

What size core did you use? Did you keep the outlet hole diameter the same? I plan on doing this later after I cut up the 300 header for clearance on the 250.

What size core did you use? Did you keep the outlet hole diameter the same? I plan on doing this later after I cut up the 300 header for clearance on the 250.

I used 2" perforated stainless. I think 1.5" would have worked better since it would have been closer to the size of the inlet coming from the headers, but I had the 2" so I used it.

I did not alter the size of the inlet or outlet at the rear. I wanted to retain the stock look exactly.

You think there's enough lip on the end caps to put rivets through instead of cutting through the weld? I'm going to just grind down the welds and pull the caps apart. More work but it allows me to tune the stock muffler.

You think there's enough lip on the end caps to put rivets through instead of cutting through the weld? I'm going to just grind down the welds and pull the caps apart. More work but it allows me to tune the stock muffler.

That will not work. Look at my very first picture. The rear end cap is double walled and welded or pressed together. The baffle (also in the first pictures, the ugly brown perforated thingy) is also welded into the end cap and is actually fully enclosed, so you have to remove the whole thing. Only way to do it is to cut both ends.

I cut both ends off and kind of boogered the rear cap. Any suggestions for cheap core? I might just have to run to the muffler shop and see what they have.

I cut both ends off and kind of boogered the rear cap. Any suggestions for cheap core? I might just have to run to the muffler shop and see what they have.
pics of carnage!:D

Stock exhaust weighs a ton and looks ugly imo

pics of carnage!:D

Its nothing bad. I was trying to bang out the pipe and break the welds around the tail pipe to remove the rear cap. it caved in the mounting studs for the rear cap cover.

http://i2.photobucket.com/albums/y5/cuongnutz/Ninja%20250/th_653FB42C-0ACD-4186-8519-26CAACEB214F.jpg (http://s2.photobucket.com/user/cuongnutz/media/Ninja%20250/653FB42C-0ACD-4186-8519-26CAACEB214F.jpg.html)

Here is where I usually get mine.

http://www.lachoppers.com/catalog/display/1136/index.html