new exhaust WOW!!!

captainrichhill

New Member
May 31, 2008
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I just build a new exhaust for my 70cc HT. I started with 3/4" metal electrical conduit then went to 1". I cut wedges out of the pipe where I wanted to bend the pipe. then I welded it all back together. I added a pocketbike muffler ($20 delivered) and it sounds AWESOME!!!!! I get about 4-5 mph (on bike computer) more speed. The outlet for the muffler is back behind me and away from the back wheel (not getting on my back rim and on my rear brakes. Thats a good thing.
I hope someone else will benefit from my post because it reall was cheap and great for performance.
 

Dan

Staff
Staff member
May 25, 2008
12,775
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Moosylvania
Venice, was just checking out your web site. Pretty work fo'sho! PantherIII is a work of art. Any problems with the fenders on the Nirve bikes? I am getting this Nirve.com - Men's Cruiser Bikes and really want to keep the fenders and live. lol
 
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Dave31

Moderator
Staff member
Mar 1, 2008
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Aztlán, Arizona
how do i start a new thread?
Once you have picked the forum you would like to post in....

Up on the upper left you will see a sprocket that looks just like the "reply" sprocket.

Except this one will say "New Thread"...click on that and enter the title of your thread and type away and then hit "submit" at the bottom.

Need any more help let me know :)
 

captainrichhill

New Member
May 31, 2008
203
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I took some pics of the new exhaust. I can't seem to post them. First it asked for the URL. I have them on my computer. Then I tried to attach the pics and it said that the files were to big and I don't know how to resize them.
Any pointers??
 

Motoschwinn

Member
Jun 27, 2008
434
1
18
Independence MO
I took some pics of the new exhaust. I can't seem to post them. First it asked for the URL. I have them on my computer. Then I tried to attach the pics and it said that the files were to big and I don't know how to resize them.
Any pointers??
I'll send you a private message with my email; send them there I'll resize them
 

Nomad

New Member
Aug 4, 2008
188
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U.S.A.
I just build a new exhaust for my 70cc HT. I started with 3/4" metal electrical conduit then went to 1". I cut wedges out of the pipe where I wanted to bend the pipe. then I welded it all back together. I added a pocketbike muffler ($20 delivered) and it sounds AWESOME!!!!! I get about 4-5 mph (on bike computer) more speed. The outlet for the muffler is back behind me and away from the back wheel (not getting on my back rim and on my rear brakes. Thats a good thing.
I hope someone else will benefit from my post because it reall was cheap and great for performance.
That's a nice lookin' muffler and pipe.... I think I gotta try to make one. Nice work....
 

MyPC8MyBrain

New Member
Aug 1, 2008
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Nice job on the pipe. That reinforces my thought about how the exhaust on these motors is the biggest thing holding them back.

I like the 1" pipe. I was going to build a prototype with 3/4" but now you have me rethinking that. Even without an expansion chamber... 20% gain. Awesome.

Rear exit mean no more 2stroke smelling shoes too ! I hate that :)
 

captainrichhill

New Member
May 31, 2008
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The bike is an old Performance Hybrid (1/2 way between a road bike and a mountian bike) The engine is a "70cc" from Dax. It's been pretty good. I ordered it when Dax was behind and it took awhile. I've replaced the engine mounting studs along with the exhaust studs with "actual steel" 6mm studs. I added an upgraded ignition wire and NGK spark plug. Soddered and heatshrinked connections in the wireing. And now it's a new exhaust. The bike has been great and alot of fun. Then again I love tinkering in the garage. I would recommend this engine to anyone.
 

captainrichhill

New Member
May 31, 2008
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The tubing was cheap. About $10 for 8 foot piece. (Home depot) Plenty of material for do overs. I took my time and tack welded as I went. I cut 2mm wedges out of the areas i wanted in the inside of the curves. If you have welded before you shouldn't have any problems.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
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Essex, UK
Interesting you get such a performance boost since it seems that you have managed to make a throughflow exhaust much as is done with the tuned 4-stroke headers on the large v-8s and such.

I do have to say it looks pretty good and very tidily done :)

Jemma xx
 

misteright1_99

New Member
Mar 21, 2008
716
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Treasure Coast, Florida
Looks like you have really cut back on the backpressure as jemma points out. You have to be careful, and keep and eye on your plug, becuase a 2 stroke without backpressure may run good for a while, but not long. Very nice job of fitting it to the frame, very clean......
 

okc_car_dude

New Member
Oct 11, 2008
7
0
0
Oklahoma City
Nice job on the pipe. That reinforces my thought about how the exhaust on these motors is the biggest thing holding them back.

I like the 1" pipe. I was going to build a prototype with 3/4" but now you have me rethinking that. Even without an expansion chamber... 20% gain. Awesome.

Rear exit mean no more 2stroke smelling shoes too ! I hate that :)
Or just get front pegs, like me... to rest those feet on when the engine's goin' ;-) I got mine for 7 bucks on ebay, shipped. around here, you can also pick them up at walmart for 8.86 + tax, or something like that. keep in mind cost of living in Oklahoma City is among the lowest in the nation, though. :p