free air R boost bottle

[200x Basket]

who was looking for it

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMESE%3AIT

[Yamahammer490]

Holic was - and he's already the high bidder.

[350x'inNY]

How does this thing work anyway? Will it fit on a 82 250R?

Bruce

[200x Basket]

i see no reason it that is should not fit. i dont think they really do much for performance.

[plkmonster2]

They lower the crankcase pressure a tad, and may be able to hold a little more air and fuel mixture. They don't do much, but you should see a slight gain.

[Yamahammer490]

A "boost bottle" is technically called a Helmholtz Resonator. It is supposed to help absorb the pressure wave sent back through the carbs, improving throttle response and overall carburation at the lower end of the rev range.

Whether or not, and how much, they work is subject to a lot of debate and there are a lot of variables in boost bottle design. The size of the bottle and length of the hose must be correct for the bottle to be "tuned" to the size of the engine. For example, if you took the boost bottle of a Tri-Z (which is about 3"x3"x4") and replaced it with a 2-liter soda bottle, the engine would run differently and, in theory, have a different "flat spot" in the power curve. (Assuming it ran at all.)

I guy I work with had a Tri-Z and removed the boost bottle because it cracked. He just plugged the hole in the manifold and remove the tube and bottle. He said the engine ran like crap until he found a replacement.

Sorry for the long lecture. I'm a recovering mechanical engineer and just can't help myself sometimes.

[3WheelsForever]

The engine ran like crap because it was getting to much fuel. After putting on the boost bottle you must rejet. Its somewhat like putting on a reed spacer or having a longer intake tube. You could put a 2 liter bottle on but the carb jet would have to be huge. The bottle also helps getting the fuel and air mixed more. Its like the old motorcycle flattrack racers with the real long intake tubes where the carb was about a foot from the head. The air and fuel got a spiral pattern going and whenever that spark hit: KABOOM.

[Yamahammer490]

The engine ran like crap because it was getting to much fuel. After putting on the boost bottle you must rejet. Its somewhat like putting on a reed spacer or having a longer intake tube.

Yes, you are right. When you change the configuration of the intake you need to rejet. The same holds true when you add a pipe. The flow characteristics are different so you need to change jetting.

I wish I would have known he was taking off the boost bottle and spent a little time trying to make it run right. I've always wondered just how much a boost bottle adds but that question has a lot of dynamics.

[mymint87]

did someone say TURBO 500?.........hahahahahahaha

[Lots_Of_Nothing]

all you free air R and other single cylinder 2 stroke guys, do know that any brand yamaha blaster boost bottle will work dont you? same thing, and you can get all sorts of different brands. its not like a custom fit thing,, except for like 2 cylinder models where there is 2 hose connectors on the bottle.

[Trikeaholic]

all you free air R and other single cylinder 2 stroke guys, do know that any brand yamaha blaster boost bottle will work dont you? same thing, and you can get all sorts of different brands. its not like a custom fit thing,, except for like 2 cylinder models where there is 2 hose connectors on the bottle.

Yea, but I am looking for old aftermarket stuff, whether it works or not, it just must be in good condition, heck I'd buy a vintage answer roost boost and throw it on the R just for the heck of it, and Hammer, that was informitive, thanks. Helmholtz regulator, eh?? LOL thats cool.