$29 ebay pipe and an hour with the welder

It finally came! After almost two weeks the UPS man brought my pocket bike pipe!


Opened the box and had no intention of working on the bike tonight but the more I looked at the pipe the more the bike was calling me to install it.

Started out cutting the expansion chamber off and had every intention of installing it like a SBP kit but I didn't like the idea of losing my kickstand and I couldn't figure out a way that it wouldn't interfere with the crank arm so I flipped the headpipe around, laid the expansion chamber along the frame and BINGO I really liked it!

Couple of tack welds and my attention was drawn to the muffler, I kind of liked how it was pointing down but the crank hit it so out came the angle grinder. I toyed with the idea of cutting the curve off the original headpipe but I looked inside of the muffler and didn't like the idea. I'm not a big fan of glasspacks on little engines, oh sure I have them on my trucks but they sound cool on them. Then I thought, "I went through all that work opening up my original muffler a few weeks ago it'd be a shame to toss it aside" so I hacked off the mounting flange, a few inches of pipe and BINGO again!

Now my thoughts turned to how to support it, I looked around and there was the pocket bike mount that was the first thing I cut off laying on the floor. A little trimming with the angle grinder, a little bending with the hammer and I welded it to the original muffler then I used a spare coaster brake strap to clamp it to the frame.

Only downside is I'm going to have to wrap the thing in header tape because I felt my thigh brush the expansion chamber a few times while pedaling so I have to get that done before spring or no riding in shorts!

Does it work? HECK YEA! I could definatly feel it when the motor "came on" the pipe. The exhaust has actually gotten quieter with it, the only difference I notice is the tinny ping from the expansion chamber, kind of sounds like a quiet dirt bike now.

The second picture is all that's left over.

One thing I left out last night was while I was working on the exhaust I noticed the spark plug cap was sitting on the plug kind of crooked, pulled it off and the brass insert came out still stuck to the plug. Set it aside and when I had the exhaust done I tried threading back into the cap but somehow the spring clip disappeared. Went over to my trusty file cabinet o' junk and pulled out an old GM HEI plug wire set, clipped off a wire end with a 90º boot, screwed it into the CDI (8mm wires are a little tight but they'll fit) and presto, new plug wire.
Couldn't find the threaded "nipple" to the original plug (I know I put it someplace so I wouldn't lose it which means I lost it) so the nice thing is you can slide the stud on the plug up between the boot and the clip if you have to temporarily.

So the moral to the story is you don't have to go buy a coil lead if you have an old plug wire or two or a whole set laying around. Check your local service station or garage and see if they have any old plug wires laying around, you may just get one for free.

Oh yea, when I ride to work I have a little less then a mile ride, topped out tonight on a flat 1/4 mile section of my ride at 31 and it's never gone that fast in such a short distance before.