Very, very sorry to ask a question about...

I got mine from EBAY boost bottle industires. Sent me the wrong manifold, but seems like quality bottle.. Lots of sellers on there just pick one...

I've been wondering if maybe the reason boost bottles don't really work on our china engines, is because we don't have "tuned" expansion chamber pipes on them? (like motorcycles & RC cars do)

__________________
Check out www.VeniceMotorBikes.com
www.myspace.com/skitzo_cfp

Thats quite a possibility. Now I think of it I never ran one of my Motorcycles without a expansion chamber(s)..

I've been trying to search for what I've read before about muffler drilling and other mods to increase performance, but cannot find it.

By the way, can anybody explain how this site's search function works? For example, I've tried to search for "gap" to find a particular post for spark plugs, where the word "gap" is clearly present, and yet NO results are present?

My only experience of these mufflers is from curiosity. Pulled out the tube from the muffler. It had an "upstream and downstream" baffle attached to the tube. I have no idea how it works, and a Wikipedia definition of how mufflers works leads me to believe there is absolutely no scientific background to the design of these Chinese parts, based on the designs of all the other components... I truly doubt they are resonantly tuned to self-cancel sound waves like a car muffler with 100 times the engine displacement which is whisper quiet.....
Where was I anyway? I feel like I was rambling or ranting or both for some reason.....oh yeah, so you drill out what part of the muffler?

Now we're talking!!!
"Yeah, so I put this part on, and could turn it on and off, so to speak, and couldn't feel a difference".....
What about those of you who swear by these things that have "pinched it on and off" to see if any differece?

I'm wondering if these boost bottles act as sound resonators. On car air induction systems, there are frequently these similar tumors on the air inlets to reduce noise. Perhaps there is a psychological effect of performance based on sound?

I'm really not trying to rip on anybody, especially since I have no opinion or experience whatsoever about these things. But for those who swear by these, could a few people provide definitive numbers which say that, oh, acceleration over a certain distance ended up with higher mph at "x" distance, or mph up a grade before/after.... or whatever, had this measureable result...well, I'd like to hear about that....without a link to the manufacturers website with their own "dyno test results", or without the old "it feels better" response, because if my engine is, say, vibrating less, or spewing fewer obscene noises while doing the same work...chances are I'm gonna say it's "working less to give the same output" or even "giving out more work for the same noise output".
Sorry to rany over this thing i've no connection with...simply trying to cull the minds of all these great motorbikers!

I agree on the psychology of the boost bottle. Most of what the directions tell you to do would enhance the performance of these small engines.

What I'm saying is they may work, but on bigger engines and how much do you wanna spend to get a performance boost you can do for free?

Now, about that baffle.... cut it in half, or remove it and adjust your carb afterwards, you will see a small improvement across the rpm range.

__________________
If it ain't broke, and you mess with it long enough, it will be.