brazed a yz80 pipe to fit on HT motorized bicycle project

I needed somthing different to do so i decided to fab a 2003 yz80 expansion chamber to fit on my project bike. using the BernOmatic oxy/mapp torch i brazed the pieces together, overall turned out fitting great. I still need to fab 2 mounts on the frame for the 2 other exhaust mounting/bracing tabs.


flowported case and cylinder, cleaned up transfer ports, widened up exhaust and intake port, 3rd transfer port added, arrows reed block kit, cns carb #61 drill bit size for jet, puch 74cc hi comp cyl. head, ramped/notched/window'd piston. still in crank balancing process.

2 vids of it running w/stock exhaust, will post updates of yz80 exhaust when i can.

http://www.youtube.com/watch?v=ZrQ38tbUd20

http://www.youtube.com/watch?v=wKmmRpmGT2g

Re: brazed a yz80 pipe to fit on HT project

Enforcerkart65 said:

keep at it. ive always wanted to use a dirt bike exhaust. can't wait to see how it turns out.

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I fabbed a universal small engine muffler on the end of the pipe that worked out perfect, i also have one exhaust mount made for the back by the muffler ill have that on tommarow. i took a short video of it running with the yz80 pipe.

Heres a video of it running.

http://www.youtube.com/watch?v=StjNDMWMdbQ

Re: brazed a yz80 pipe to fit on HT project

i honestly have no idea what kind of power this this makes i am unable to ride it until my broken back heals more, as for re shaping the pipe no i didnt. i had a banana chamber exhaust laying around so i cut the cone part off (cylinder side with exhaust tubing welded to it) i cut enough cone off to fill in the diameter of the yz pipe because it was bigger. any one can do this, i have no experience in brazing and you can see it turned out!

Re: brazed a yz80 pipe to fit on HT project

Enforcerkart65 said:

Thanks. Sounds easy enough to make with some fabricating which is what I love doing. Hope your back gets well soon.

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Btw I bought the 2003 yz80 exhaust off ebay for a smoking deal of $25!

Re: brazed a yz80 pipe to fit on HT project

Welcome to the forums! And thanks I'm glad I could help out, iv never found too much info on fabbing up a pipe, everyone's got the same stuff. Nothing better when a experiment works out! Except now I need a new crank because I messed it up trying to balance it lol