Custom built x pipe

GoldenMotor.com

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon
So while I was at work last night digging around looking at just about every expansion pipe on eBay I could find, I found a style I thought would work good n saved them to my eBay. My dirtbike riding roommate had tossed a old ktm 125 pipe in my scrap pile a couple weeks ago. He said I could use it and I didn't think it would work. Well last night after seeing a few custom built pipes on bikes my brain started putting it all together. I had bought some cheap junk $50 pipe off eBay like two months ago that wouldn't fit my bike because the cylinder head was to tall. Well I went and grabbed the ktm pipe and started visualizing the build with the already imagined ideas from the threads I read last night and started going to work. Grabbed my angle grinder and dremel n went to town. Here's some photos. Gotta figure out how to upload again first tho.... lol
 

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon
First I started with a eyeball fit up. Kinda getting an idea of what I needed to do. Found that I needed to cut like 3"s off the header portion that mated up to the 125.





I started cutting Sertain parts off that I thought I could use to make the pipe fit up.







I was starting to get an idea of what this was going to look like. Couple issues I was facing were that the front tire was extremely close to the pipe. After making a few more small cuts the pipe cleared the front tire with a small but acceptable gap. The pedals cleared just fine.
 

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon












At this point I had cut my hands a few times on sharp metal from sorta rushing the job from all the excitemement of finally building a good pipe to put on my MB lol. Iv always wanted to get creative and build one but hadn't had the motivation to do it or the idea storming in my head of how the pipe would look n such. The anticipation =D
 

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon
So after I got all the pipe pieces figured out I strapped the pipe to the bike with zip ties to hold it in place while I busted out the welder to tack the thing in place. Now I don't have a mig but I do have a 30-275 amp arc welder that Iv built everything with so welds don't look beautiful by any means but it holds together. I haven't gone back thru and cleaned everything up yet either.









So I got it all finished up and put on the bike. I had to put the silencer on, this thing is super loud with it. I also cut and turned the pipe to point more toward the ground and out of my legs way.

So....!!!!! I started it up, took off out of the drive toward my favorite roads to go ride down. Right out the gate hit 20mph and it started to pull pretty well straight to 40mph with ease. I'd say it's a good improvement compared to what I was seeing with the old black ugly eBay pipe. Now the eBay pipe didn't have much pickup but would hit 46mph. This pipe has a ton more pickup off from 20-42 mph then that's about all it wants to do. I don't know my rpm range for speed but I'm running a 30 tooth sprocket and have to pedal to about 10mph to take off out of idle range rpms lol. At 20 the bike is at a low rpm but I can cruise. I'm thinking I'm gonna get a 36 tooth and see how I like it. Years ago I had a bike with a 36 tooth and it would do 47 wound out to the max. It may have been running a bit lean tho.... lol. Any questions feel free to ask. .shft.