boost bottles: yay or nay?

According to what I read, the boost bottle was designed to be installed on a reed valve engine only. It was short lived on real motorcycles and never was listed as making an engine idle or any mid range improvements. It had a very narrow band of hp improvement if at all. It needs to be installed as close to the intake as possible within an inch, also was intended for a twin cylinder engine. Have fun, Dave
 
That has been my experience on Yamaha and Kawasaki two strokes. The bottles we used to use were White Brothers, they had special manifolds where the nipples on the boost bottle actually connected to rubber manifolds between the carb and reed cage.
 
have you checked out qurakdude's youtube post? his engine sounds incredible, and all it looks like he's done to it is install a decent air filter and a boost bottle. so there is proof that they do work correctly... i'm just not sure how. i've applied aerospace grade sealant to pretty much the entire intake manifold/carby/boost bottle area, it'll be dry by tomorrow so i guess i'll have to wait til then to see if it works or not.
 
cool, my boost bottle works. it WAS an airleak, but i couldnt tell you where, since i sealed everything. i think it does help the engine, and i can detect a certain amount of acceleration improvement in the mid-revs, but other than that, i got more performance out of installing a hotter spark plug. still, it looks cool. im happy with it.
 
There is no sense in belaying the point. But there is a reason the expansion chamber works and a reason the a Boost Bottle works. None of the criteria has been met on the little Chinese engine. If there is any improvement in the running with or without the bottle it is probably a quincedence. I have been tuning high powered motorcycles all my life, I saw the boost bottle come and go. There was never enough improvement to warrant its use. There is info on the web that enplanes how it was to work, one of the important details was never allow it to trap fuel, all the ones I have seen would hold a full pint. Oh well there still selling them. Have fun, Dave
PS: I wish you could hear my engine run, with all the porting and carb mods, I think you would like the sound. But it is not about the sound, how well does it pull the bike? Up Signal Hill with no pedal. Quark's bike is nice but it still revs slow.
 
Good to hear Nick. I wish I could get you one of my cylinders so you could have a go with it. A two stroke is all in the port and the pipe. The pipe uses a shock wave created from sound, so they have to be tuned to a certain speed to use the shock to move fuel. The distance from the port and the second cone in the pipe is critical, you don't look for sound, its performance but the sound will be there. The boost Bottle uses a shock wave from the reeds slamming shut, the pulse is timed to the next intake, and assists the movement of charge air. On a Dino the increase was so small we left them off. Have fun, Dave
 
I waited to post here until a friend could get access to a radar gun for testing. Tests were run using my silver beast. I weigh 212. Runs were shorter because I didnt want to blow the cheap ebay "boy go fast" engine up. Tests were best at low-end. Diminished at hi-end.

Test 1. Steep hill 22deg. incline. 200 ft from a dead stop.
________________________ No boost______With boost bottle
_________________________16 mph________18 mph

Test 2. Flat grade no wind. From a dead stop.
________________________ No boost______With boost bottle

________________50 ft______11 mph_______13 mph

________________100ft _____17 mph_______18 mph

________________150ft_____ 21 mph_______ 20 mph

________________200ft_____24 mph_______ 23 mph

Test 3. Flat grade no wind
slowest speed without the
bike-jerking
________________________ No boost______With boost bottle
__________________________3mph_________2mph

Test 4. Bike at Idle.
________________________ No boost______With boost
_________________________smooth_______smoother

Test 5. Flat grade no wind.
Hydrogen/oxygen Boosted-
from onboard hydrogen fuel cell
Injected through the
boost bottle intake port.
(Along with the throttled gasoline oil mixed @ 20-1)
____________________________ No boost bottle.
_____________________________200 ft 30 mph wow! 6 mph faster than above. Hydrogen/oxygen supercharged the fuel.
Backed-off before I blew her up.
 

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i would concur with your results, graucho. i feel like my bike responds better in the low and mids, but it lacks more than it used to up high. ergh, anyway, im just happy it works at all, and i didnt waste my money on it. now im off to tinker with my new project. will keep you guys posted (i have to teach myself how to weld before i can start it, lol).
 
but if it IS an airleak, why does the engine die on its own after 15 secs?.

Residual fuel in the intake/carb/crankcase. Once it's used up, the engine leans waaay out and dies, a very unhealthy thing for two strokes.
 
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