Spree new pipe/air filter/belt swap review

[bradbutlernc]

Today i added an expansion chamber pipe (20$ ebay pipe for pocket bike) cut the stock muffler off, cut some off the pocket bike pipe, and welded the 2 together. Still gotta make a support brace for it. Hangs kind of lower than i like but for 20$ it works great. Actual ground clearance is about 5". Also swapped old belt for dayco ax24 belt. Air cleaner is from a chinese 50cc and connected to carb via a 1" hose, oil pump is blocked off and am mixing 32:1. Think it runs a little lean now so i need to jet it. Going to mill the head .030 soon and rejet then. Also drilled the cover for some airflow to maybe help cool things. Im not sure of new top speed but with pipe and air filter and belt i picked up atleast 10mph, pegs the speedo


Also, sounds sweet now, and after about 15mph you can really feel the power kick in.


Heres some pics.

[bradbutlernc]

Heres the pipe http://www.ebay.com/itm/HP-Exhaust-Pipe ... 1c2a44b847

[roflwaffle191]

I'm really thinking about doing this as a first upgrade, the pipe is cheap and i know i can weld it up in an afternoon. Any updates. it it still running good?

[patthesoundguy]

Getting the header length right is key here. Look at the pic of the two pipes side by side how they match in length kinda. That was a good move. Something to watch for in the Chinese pipes is how much header pipe is protruding into the chamber, they are never right. Here is one I did for my express last year worked well until I ported it and that made the pipe hit way too high in rpm to be useful

You can see the couple inches of header pipe in to the chamber. That really can kill the pipes performance. The pocket bike that pipe came from sounded all wrong and the pipe never came on at all. It worked on the express after I fixed it though. If you can not weld the pipe on until after you get the header length worked out thats the best way. In was able to side the chamber over the header and it was a good enough fit I could ride then come back cut some header off and try again. It will work great or it will suck, bummer you have to hack a good exhaust to find which one
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