Stock exhaust mod

[roughrider01]

Well pretty soon im getting a new full exhaust so i thought about uncorking my stock exhaust. Well after i cut off the spark arrestor and cone off the hrc encap i deciding to ungut the slip on. If you ever look down your stock exhaust you will see a series of ports/ cylinders. Only two of the four cylinders actually breath out of the exhaust the other two are just baffles or something. Well today i removed the whole inside of the slip on minus the packing. I know with my DS650 when i got my modded end cap there was nothing in the muffler it was just a straight pipe with packing on the walls and its made my DS run 100% better. I didnt really get to test mine out yet, but it made it alot louder to say the least. The only reason why i did this is because im getting a new exhaust so i dont really care what performance i lose or gain, just something to do when i was bored. Ill let you knw how is runs tomorrow. All i know is after 3 hours of trying to get the thing ungutted and bleeding from various parts of the knuckles and wrists it better atleast helped out alittle..lol. I never heard of anyone modding there stock exhaust so i thought id post this. It feels like it has well enough back pressure, that was mainly the only thing i was worried about. Tomorrow i might have a pic of the inside of it now, theres a tiny screen left in the way beginning of the muffler, im not to worried about that.

Updates to come.

[250rtone]

It's been awhile now so how about that update on the gutted stock muffler.

[roughrider01]

Personally i think it improved low and mid range some, its feels like it pulls harder. It seems like i got to be alot more careful in low gears with the throttle because the front end likes to come up alot easier now. Its a quite a bit louder now so i cant hear the engine at all so maybe im just less scared to rev it out and am running it harder, i dont know. I got a 190 main, with HRC kit and it seems to be getting alittle hotter, the fan comes on a bit more.. but its been humid and hot up here.

Well because of this anyways, im gonna hold off on getting an exhaust for a bit... it pulls plenty hard enough for me.

Its not a fun job to uncork it to say the least, but if you got some time and patience you might wanna think of giving it a try. After you see how bottled up it is in there you will figure that just a different endcap isnt going to cut it, its like trying to breath out of a straw thats kinked.

[250rtone]

Do you have a pic?

[roughrider01]

I can get you one by the end of the night. Taking it out probably took two hours.

[250rtone]

I just took the first "layer"out and i noticed a change in the tone of the exhaust. I then drilled a few holes in the plate inside that has the 2 smaller pipes through it, took it for a small ride and it has crisper throttle response plus it now sounds like i think it should. I don't know how you could have gotten the last "layer" out, it's tough. I am going to remove the lid, rejet and install a white bros filter and then see the diff. I am also going to get a longer drill bit to drill through the screen deep inside. This thing makes me feel like a kid again!!

[roughrider01]

Well if your like me and like messing around in the garage, it was actually kind of fun to do. I used a big flathead screwdriver and a hammer to gut it out. If the sawzall would fit in there it wouldve been a heck out alot easier. Half way thru the job i was like what the heck did i get myself into but im happy with the outcome, she sounds mean now.

I didnt get a chance to get pics, battery was dead in thecamera so ill get them tomorrow.

[250rtone]

Thanks,

[roughrider01]

Heres a pic of of the inside of the can, the picture is a little deceiving. The screen is actually deep down in there, its not as close and the pic shows.

http://img78.photobucket.com/albums/v237/roughrider01/DSCN0041.jpg

[RuffRyder]

I took the spark arrestor out and it looks like this. How did you guys take that part out?? Hammer and screw driver is one way..but how?:confused: BTW check out the custom grab bar..
http://www.imagestation.com/picture/sraid116/p456bb8a90dda826bc587b98f07c716e5/f8a5c584.jpg

[250rtone]

Yes, you have to beat it out with a hammer & screwdriver. What is the reason for the funky grab bar??

[RuffRyder]

I like to ride 12 o`clock style and found out the hard way that the stocker is too skinny... I didnt rejet when i took out the SA but my guess is that you must re jet after the rest is out..correct?

[250rtone]

Yes you should.

[WhiteZee]

what main jet should you run if you just pull that first layer out, so it looks like roughriders picture?

[Pappy]

Originally posted by WhiteZee
what main jet should you run if you just pull that first layer out, so it looks like roughriders picture?

you probaly wont have to rejet unless you remove the airbox lid or run an aftermarket filter.

if its stock lid and filter stock jet or a 125 main

if youve removed the lid and such, id start at a 170.


it seems to me like the R isnt corked up as bad as it may seem. opening up the exhaust doesnt affect the jetting too bad at all. BUT if you touch that airbox she wants fuel!