Boost Bottle

I'd like to say a few things.

First off for the question that was asked. "Has any body tried a boost bottle on a whizzer 4 stroke,or do they only work on 2 stroke engines???
Bill b"

I'm not sure if anyone has tried one on a 4 stroke "wizzer" BUT if you get the size right, and your manifold is not already tuned well, then you can increase performance... ON A 4 STROKE. So there are some "if" "ands" and "buts" :) but yes... it's possible that it will. The second part of my answer is that... most of the gain you will see form the bottle would be bottom range and a 4 stroke usually doesn't lack in that area.

"Hi, well, the boost bottle is strictly to "pulse" back into the cylinder increasing the charge in the head, on a 2-stroke. It will have no logical effect on a 4-stroke engine.

performance concepts are in most cases completely different."

Wrong in a few ways. The boost bottle does more than that. The scavenging of fuel and air was actually meant to make the engine work "normal" at low RPM and not to increase power. If you don't understand the inner workings of a carb then it won't help you to read the next part.

The problem in the intake is this. Air flows threw the intake tract as the engine demands it... ( 2 or 4 stroke ) then when the engine blocks the flow ( a valve or piston ) the momentum of the air causes a positive pressure to build on the engine side of the carb and intake manifold. At low RPM the air "bounces" back over the jet tube ( or whatever in the carb supplies fuel ) and draws out more fuel ... just as it did going in the first time. This causes the mixture at low rpm to be rich.

The bottle is simply a space for the pressure to relieve into so that it doesn't pass over the jet tube and cause the enriching problem. The size is important because the bottle will fill in a given time depending on it's size. For it to work properly it fills and starts to reverse and come back out just as your engine starts to demand another intake charge.

Other than that... performance concepts are the same ... more fuel and air = more power... till something gives or melts :)

"If you had read this stuff, one thing came out in the first page that the boost bottle PROBABLY (read WON'T) work on a reed-valve engine."

90 % of the boost bottle engines that I've seen, and that's more than a few, are reed valve. Reed valve has very little effect on an engine "needing" a boost bottle.

"Ok, now if the reed (in between the engine and carb) would stop the action of the bottle, what do you think might happen with our intake valve? A good running 4-stroke will NEVER sneeze into the carb. We also do not charge our crankcases with mix to run, we port gas mix directly above the piston."

If you've read any of what I've written then you know why this is wrong... It's correct that a 4 stroke won't "sneeze" back... but neither does a properly tuned 2 stroke AND as I have explained .... sneezing isn't the cause for the boost bottle being needed. More so the momentum of the air.

"In reality, there are very few similarities in 2-stroke and 4-stroke tuning and performance."

They are all the same ... just a different way of getting the same result. To make either engine run, and run well, you need proper fuel, air, compression, timing of intake and exhaust and ignition timing. Everything you need to make a 4 stroke work well you also need to make a 2 stroke work well.... it's just different ways of achieving those things.


"Hi, now for me, that makes sense, even tho that technology does not work on any valved engines,
Thanks,"

Again ... wrong. "valved engines do benefit from a bottle.... Many have.

If any of you don't believe what I'm saying then do some research outside of this forum. Tho I'm not cretin who "invented the idea" Yamaha popularized the bottle and has used it on MANY reed valve engines. It's been used on 4 strokes ( many British cars ) and multiple cyl engines as well as singles. Fuel injection and "proper" tuning of intake lengths and volume has made the bottle less popular these days but it still has it's place when used when it's needed.

Understanding how something works, in detail, is often the best way to maximize the benefit if any. For example... putting a turbo ( I know this is silly but a great example ) that flows 100 CFM on an engine that demands 150 CFM of air is only going to harm performance. If your intake pulse is tuned to work properly then a boost bottle will only harm performance.

I am passionate about problem solving and enjoy wrapping my head around the idea of what happens in an engine. Hope I haven't offended anyone.
 
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Home-brew, thanks for your addition to this thread. Gives me a lot more insight into how the boost bottle is supposed to work.
Thanks
Van
 
Well the Whizzer intake goes to the combustion chamber there are no scavage ports nor is there a transfer of pressure from the crank housing(Lower end) so the back pressure is probably a lot quicker and less actual backpressure flow. so a booster would probable leave the oposite of a bottle neck kind of to the point of flooding Id think.
 
Wow, I just learned a whole bunch today... I finally figured out what those tubes were on Rick's bike as well as the bikes he builds. I finally asked him and now, I want to build one... I was gonna call Rick and ask him but decided to poke around on the net 1st, and sure enough, it brought me to this thread. Thanks Rick! You'll be seeing another addition to my bike next time I see you... I still laughing about on how I lost power on my bike today... Just when I thought I had another engine failure, it was just the air-filter, halfway sucked in the carb. That probably happened today when you asked me to rev it up high like that... I'm gonna drill another hole in that air-intake manifold tomorrow morning before I take off from my girlfriends and to see how the bike runs. If I can get that carb straightened out and a proper shim made, I'm going to keep it on that engine. I also have noticed that my bike is not gobbling up as much gas as it used to. I still have wayyyy over a half tank.. Usually, when I do all of this running around, I would be at less than a half tank. I also like the idea of that carb with the dual jets, so I think that when I make this booster, I'll take full advantage of the dual jets. If I understand correctly.. with this 'sneeze' from the engine, it is probably fouling up the flow from the 2nd jet due to the vacuum action and the time it take for the gas to get siphoned up that tube. The 1st jet would be unaffected as it is on the bottom... We'll see... I'll make that booster and to see how it runs. And in case the other MB'ers are curious, the original carb gave out due to wear and tear, 1 of the fingers went inside and locked the engine up... apparently, the timing and the positioning of that finger was just right, it locked itself up between the piston and the cylinder, but with very minimal damage. just a slight scratch on the piston, slight aluminum deposit from the finger on the cylinder wall... It was a quick cleanup and repair that a fine flat file and sand-paper could fix. Even though the skirt of the piston got slightly dinged in, I just simply looked for the highest point from where the ding was and just lightly filed it down and then sanded and buffed it out.. Now about the carb... I just can't MacGyver it and fix that carb, but still pulled a MacGyver.. I got some ducting tape, used that to make a shim on the intake tube as the only carb that I had available that would work on that engine came off of a Morton Moped, and the tube clamp is bigger than the one on our bikes. Well, **** yeah! It even has more power too. I dunno... Next time I am at Rick's, We'll compare it to the carb that came with the engine. Anyways, enough of my rambling and thanks Rick!
 
The Delorto double pumper is a **** of a carb!

Yes no prob Bud. That bike is something your kid will ride. Soon enough.
Yeah it sounds very consistent in the mixture from low to high. With the Normalizer/Booster it will be a new break in so Id do it while your Re-breaking in that Silver Eagle. Well Im talking to Nan tong Jiali they teamed up with Hua Sheng Shan on the 4 stroke and they just did a test of the new ,what appears to be, Bullet proof Tranny!
 
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Boost bottle confusion

Dear Wayde, this is 4-stroke Whizzer area, but I will answer your question anyway just to be a good sport.

Basic math: above I stated that your displacement should be equal, correct?

If your 9oz bottle holds 9 LICQUID ounces, how many cc's would that be?

1 Liter = 1000cc's
1 quart=16 us ounces
one US quart=946cc's
one 9oz bottle=473 cc's

473cc's + volume inside the lines and fittings do NOT equzl 69cc's?

Mike
I seem to remember there being 32oz to 1 quart. Which by my quick estimation would put a 9oz bottle closer to 270cc
 
@Still learning, I understand your important information couldn't wait and you wanted to share it with the world.
But this thread is 12 years old. Learn to check the dates
 
Yeahh. Jeez! 🙄
Not to mention that a 9oz CO2 bottle is to contain a maximum of 9oz weight of carbon dioxide liquefied under pressure, not 9 fl.oz of anything; making this a moot point indeed! 🧐

Had to read the whole thread in order to make that "clever" comment. 🤣
 
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