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2 use a boost bottle, or not?

10K views 20 replies 10 participants last post by  Paulie B 
#1 ·
I have been looking into the actual advantages, and/or disadvantages of running with a boost bottle?

Some of the info, and discussions I found on this subject weren't very helpful.

From what I have gathered a boost bottle can help throttle response into the powerband, and can be a bandaid for poor jetting?

Of course a lot people said that the engine looses topend with the boost bottle, and remove them.

So I have to wonder? If the boost bottle is a good bandaid for jetting issues, and you ride on trails with some extreme altitude changes would it not be better to run it, and not have to stop, and change you jets every 20 minutes??

So in retrospective, I'm looking for some feedback.. What do others think of boost bottles?
 
#2 ·
you should not have to change your jetting with an altitude change unless it is very drastic and you will be riding each altitude for many many hours. get it jetted right and you will be fine. boost bottle = waste of money and less hp $.02
 
#10 ·
That's good to know. Where I ride you can go up, and down within a 1000ft altitude change. I never thought about having to change my jets, but we go out for 4 hours a trip.. I have always wondered about leaning it out, and running to hot? But it makes sense to me that if you get back into the altitude your jetted for right away, it should have no ill affects..

IMO they are just another place for a leak to start, i dont even use the manifolds with the boost bottle inlet, i get rid of all of that, no leaks for me :)
Well the motor that I'm speaking of is a 83' Yamaha 490. It has a stock boost bottle, and seals well. I don't even know if there's an intake for the older 490's, that doesn't have the provision for the hose??

I'm not even really sure I understand what the boost bottle does? I know it sucks up unburnt fuel (spitback), and it gets sucked back into the mixture under heavy throttle.
I don't understand where you loose power in this?
 
#7 ·
no you didn't!


:D
 
#6 ·
I agree its a gimmick, i bought a the boss intake that eliminates the need for the crossover tube or boost bottle... the cross over is built in... i think the boost bottle in theory was supposed to increase volume but i dont think there have been any studies proving it. You should only need to change your jetting if your altitude changes drasticaly like 2000ft or more would require a change. remember towards sea level and your need to go rich, increase in elevation you need to lean
 
#9 ·
it does increase the volume. but if you think about it how much will that help? the only time there is "dwell" so to speak is at a very low rpm, maybe not even then. and when you gas it, it can get a quick burst of air without having to be sucked through the filters. after that split second it is useless. whats it going to do then but cause intake turbulence and a loss of hp IMO.

junk!
 
#15 ·
it is deffinatly a waste of your hard earned money. i do believe that it was originally intended for a completely bone stock banshee, with the boost bottle being the absolute only mod on the thing. it was said to have helped the lack of bottom end power. i can neither confirm nor deny that claim being that i only ever had one, and that was brand new. i put pipes on it before i ever even rode the thing,lol.
 
#18 · (Edited)
you want a straight shot ideally with a bullseye and typically a short distance from carb to jug for the strongest punch ...a boost bottle on a single is a waste .on a twin it is a more to equalize pressure and balance the charge out on multiple cylinders running off the same lower end than anything ,different volume bottles can alter the powerband very minimally shifting the rpm somewhat here to there but nothing youd see or feel in the real world .basically the issue is it causes turbulence and reduces intake velocity .sometimes what sounds good i n theory doesnt work i na practical sense.. a boost bottle is a prime example of this in action. i realize its a different engine but for what its worth i know a member who gained 2 hp by *removing* his boost bottle and putting a factory balance tube on his banshee while testing on a dyno. a bottle can vibrate and cause a crack on your manifold risking engine damage from an a airleak



 
#20 ·
Thats some good info right there..

Thanx man. :thumbsup:
 
#21 ·
Either get an intake from an earlier bike or you could simply goto true value or another hardware store and pick up a rubber stopper and a hose clamp.
Another drawback to the boost bottle is they are 'tuned' meaning when ever you do a performance mod the boost bottle becomes useless.
 
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