black bottle on gas tank ?

[cleopatrisha]

I'll try and describe this the best I can. On my '81 yz250 I have a black plastic bottle container thing attached to the right side bottom of my gas tank and there is about a 9/16 inch dia. hose that goes from the bottle thing to the intake boot on the carb. I am wondering what is this for, and do I need it?

 

[XRpredator]

ah, the ol' Boost Bottle!

Yamaha had a special name for it, but for the life of me I can't remember what its called, and I'm pretty sure you need it.

 

[zoommx]

YEIS,
Yamaha Energy Induction System
Need it?? Might as well leave it on, some quad owners still use the things. Supposed to increas low end torque I think.

 

[MX86]

i guess it was supposed to act as a reed spacer or somthin. mix up the air as it flows in and out.. do you need it? no.. just need to block off the hole. is it worth it? not that i felt. makes no difference IMO.

 

[cr250mMxer]

it doesnt do any ting they dont work

 

[wirefryer#85]

Had those on the YZ490's as well.

Put a small NOS sticker on it and have fun with the tuner crowd :)

 

[2 strokes for life]

The boost bottle will make a difference but not a substasial one.

 

[pryor]

I have never had one do anything but take up space and be one more place for a leak. Does any one know how they were supposed to help power?

 

[MX86]

http://www.eindiancompanies.com/images/resonator.htm << little info on the YEIS

 

[ZOMBIE666]

many yamahas had em, from the ysr 50 to the ITs and they DO work. its just an intake resonance chamber. i put an aftermarket boost bottle from a banshee on my old RD350 and the differance was clear :cool:

EDIT:damn should have looked at that link first, speak of the devil