..stock exhaust modification?..

[wordslinger]

..what effects, positive or negative would there be to cutting open the stock 4t exhaust, removing the catalytic converter materials, and welding the exhaust back closed?..

..i've heard such terms as back-pressure and resistance...and then i think of such items as headers, cherry bombs, etc...on 4-stroke engines...

..i know that afterward, if successful, the process would require further carb tuning, but other than that???


peace

[zombie]

I think it is a fine idea. I believe the header pipe on the scoot is long enough to handle the pressure issue. the only surprise would be the "tone" you get at the end. If you deceide to open it. some carefull study of routing the gasses may be in order to get the least restrictive "true" path. How do you do all that drawing/writing overlay stuff on the screen? That would sure help me answer some of these posts. If you can get hold of some decent stock it is real easy to form your own chamber or casing reuseing your existing header. In the 2t tuners books there are some basic guide lines for dimensions, and if you didn't catch it I found a link to 4t pipe dimensions. I think anything you do to open it up would be a plus.

[Shaka]

Zombie- A simple way to draw on pictures is to open them with Paint and you can draw on them all you want!

[zombie]

How do you do the tpying/arrows, and stuff like that? Do I have to down/up load the image to the site like in doing photos? I have crayon marks all over the screen but you guys never seem to see them!

[Shaka]

I'm sure it's a pretty archaic way of doing it now a days, but I use Paint for re-sizing my pics as well.  The pics are just saved on my computer.  If I go to - File. . . Open, I can select the pic to open.  You can write text on the pic by using the "A" button on the left side tool bar.  I think for arrows you have to draw them yourself.  If you go to, Image. . . Stretch/Skew you can re-size the entire image.

[zombie]

I'll give it a try, but I think the crayons are easier for me. I have a very steep learning curve w/ some types of programs.

[mikrron]

if you cut down the back round end with the little exhaust muffer (i mean cut it right where it was welded) you will see a wall with 2 holes:
one hole is for gases from the engine , one hole goes back into the exhaust to the "catalizator".

si with that part removed the gases wont turn back into the "catalizator" , they will get str8 out
i am not completly sure but i saw it once and i know 80% i`m right

i don`t think it will boost your scoot.. and mention the sound?  sh** ! that`s so annoyng "pr pr pr"

take a look at this empty muffer running ritch (50Euros)

[wordslinger]

..dang, i like that exhaust....

[zombie]

There are PLENTY of "mufflers" that will fit your pipe. I mean cutting the header to fit the muffler on the scoot where you can mount it. Search the Ebay scoot mufflers/exhaust's. W/ the air induction, and extra jetting I think you will be posting to ask if burning your shorts is normal!

[wordslinger]

There are PLENTY of "mufflers" that will fit your pipe. I mean cutting the header to fit the muffler on the scoot where you can mount it. Search the Ebay scoot mufflers/exhaust's. W/ the air induction, and extra jetting I think you will be posting to ask if burning your shorts is normal!

...lmao....yu so funny...

 

[mikrron]

i need to mention that the scooter in the video above is crazy!
it has done this bangs since new with the stock exhaust (lame sound and no flames). We just coulden`t find out why! But who cares? Cause it`s awesomeee

[zombie]

It's all in the open muffler. Most 4t's will backfire thru the exhaust if the timing is retarded also

[mikrron]

we did the timing again and valve clearance also

[zombie]

The only other thought I have is the exhaust header may be too big. A thinner header will force the gases to move out before expanding as much.

[wordslinger]

..well, i gave up..and that was not easy to do...

..there must be something to that "back-pressure" thing on this biatch...

..never could get the perfect combination..i'd think i had it, then the backfire would return...

..so i cut the muffler back open, made me a baffle piece replacement...welded it in and welded her shut...

..went back to my 1.02mm jet...and now i'm back to the screamin' lil beastie i had before i started cuttin on my muffler...


..gonna get me that 20mm carburetor....