Exhaust mod = performance boost

[mrsaxman99]

augi...try this

My CDI/coil/spark box came undone (I didn't realize this)....so it was just kinda hanging off the frame...not touching anything. Now I don't know if it's coincidence, but I can't get my bike to cut out at high rpm.

I wonder if vibrations at high rpm might have caused misfiring due to bad spark signal.

Though, this is the first day above 60 degrees out where I have ridden...so it could also be due to hotter running temperatures...I could see where a cold engine would miss at high rpm.

Anyways augi...try dangline your CDI off to the side, and see if that changes anything.

Between the two of us, we'll figure this thing out!

-Chas

 

[gone_fishin]

the first mod i did was about spark...shortened the stock plug-cable, wrapped it all up in electrical tape, after break-in i bought a new ngk plug, i've never doubted my spark, it's ready to burn more, no problem

 

[psuggmog]

Augi, too bad I didn't read this post before going to the old bike swap meet yesterday. I could have brought orifice drills and a pin vice. We could have enlarged your mainjet at the meet.

 

[srdavo]

don't tell anybody.....

I did it..... I bored the jet in Rusty's carb. I'll start a new thread.

 

[SpeeDemonX (malta)]

will this reduce my performance? the diameter of the pipe is bigger than the outtlet hole of the muffler. i am just fed up cleaning the rear wheel of my bike because the burnt oil just spreads all around the whell especially when there is no wind

 

[Large Filipino]

Just wanted to say I finally did that muffler mod and yes it's louder but woah man it pulls hard now. And in my case it's not cutting off. It just has more power now. I've been running the castor oil so the inside of my muffler was just caked with tar. I did a good cleaning and cut off the tube down to an inch from the cap. I think I did this mod for lately I've been finding myself peddling more around small hills,but now after the cleaning and the mod that the dax site explains in detail it just pulls and pulls.

 

[Large Filipino]

Tried to edit but too late it seems.
This is the one mod that has improved performance the most for my bike thus far. The other mods helped a lot but this one changed the whole personality of my bike. In fact,it's so powerful now that it can breathe,it pulls so much that I'm truly wishing for some gears. Maybe in the winter I'll splurge for that 36 toother cause I know it can handle it. I wonder though if bikers on the trail will frown more,cause it's definetly louder.
But louder means manlier har har har har!!!!

 

[alesterfeind]

I did this mod too. I have two caps to the muffler, one with the baffle and one that I cut down about 2 inches from the cap. I can't really say it made much difference on mine, but it sounds cool.

Like you Large, there sure was a lot of tar in there. Any suggestions on how to clean it?

 

[JemmaUK]

will this reduce my performance? the diameter of the pipe is bigger than the outtlet hole of the muffler. i am just fed up cleaning the rear wheel of my bike because the burnt oil just spreads all around the whell especially when there is no wind

That modification shouldnt drop performance by much, but it might be an idea if you get the longer pipe which looks very similar to that fitted on the old underbone mopeds like the xx50 series by Honda and is available on some of the chinese kits. It extends out to somewhere around the tail end of the frame...

http://www.grubeeinc.com/USA/SkyHawk.htm

A different option is as follows.. obtain some brass pipe that is equal to the bore of the stinger on the exhaust. cut down the piping you have used so it will make a tight short joint between the two.

the next part can be done one of two ways. The most effective way is to use a short length of the pipe and put it through a pipe bender so that the exhaust exits to the left or right.

The other way is simpler, and maybe as effective. take a short length of pipe and block the end then cut two ports horizontally opposite each other. This should feed the fumes out to the sides of the bike and not straight onto the tyre. The easiest way to make the ports is use the biggest bore drill you can and drill it through slowly.

hope that helps..

Jemma xx

 

[Steve]

I did this mod too. I have two caps to the muffler, one with the baffle and one that I cut down about 2 inches from the cap. I can't really say it made much difference on mine, but it sounds cool.

Like you Large, there sure was a lot of tar in there. Any suggestions on how to clean it?

A good way to clean the tar from the muffler is to soak it in antifreeze in a crock pot set on low over night. Make sure it is outside because the fumes are toxic, and also, don't use the crock pot to cook food in ever again. They sell cheap crock pots at walmart for just a few bucks.

I also fly RC models and our engines get really dirty like the mufflers if we use fuel with castor oil, and the antifreeze in a crock pot reall cleans them.