2 Stroke Mistake

[Groundhog]

Description of error:

Thought I would be creative and modify the outlet location of the expansion chamber on a tuned exhaust.


Purpose:

Made a real nice custom fit of a Chap 292 with a tuned exhaust in an old Attex.


Result:
Lost about 1/3 power with my rocket scientist attitude!


Lesson learned:

Do not assume the factory design of a tuned expansion chamber is easy to redesign, or even worse "Improve upon".

[Don]

oops. Any way to put it back the way it was?

[techfx]

I had to do that to mine (since the manifold was hacked/welded to a transplant engine w/ higher cc's than the exhaust before I bought the machine). It turned into a pretty expensive, time consuming affair. I ended up with a Rotax 440 muffler/tuner combo. Gutted the muffler and shortened that part of the pipe then, added a generic muffler after a 90 degree bend. It's still beter than the previous owner's setup. I haven't had a chance to give it a good test run.

[Groundhog]

Well, I returned the tuned exhaust to original outlet location and performance came back! What a lot of work that was, and it is no longer pretty. Guess I will be hooking up with George for one of his used ones, paint it and leave it alone!

[jpswift1]

That's just how you learn......I've made plenty of mistakes too, so I know just how it feels. Glad you got it back up to par.