Yeis?

[ickfinger]

What gives? I know what it does, how its mounted, etc. But how come I find articles referring to it on 82 yz's My 82 125 doesnt have it, but in Daves tests and ariticles home page, it shows a 125 without it while stating it's on there. There's also a picture further down the page of an 82 250 with and without it! I know my 82 490 had it because I can remember moving it out of the way every time I needed to replace the plug(frequently). What gives? Is my bike missing it?

[Helmet_Hair]

My understanding of the YEIS was that it was only on the air-cooled, non-power valved IT's and YZ's. I don't think I'd seen them on the liquid cooled bikes...but I'd heard some MX guys continued to run them on their early liquid cooled YZ's.

[ickfinger]

I saw a pic of an 82 yz250 sporting one and in the article it clearly states every big yz had it! Maybe there were pre production and production bike pics, and the specs changed?

[buzzard111]

do you mean the "energy induction" bottle? i remember them from the early 80s yz 80s

[ickfinger]

yes, the energy induction bottle

[Hawaii-Rider]

actually known as....

Boost Bottle

Running one on my 1982 IT250 (stock)

yamaha had them for a while on their machines.

Intake boot would fail around the boost bottle hose junction and due to the cost, many would take them off and just run a standard intake manifold from the Carb to the cylinder.

Of course if you remember those then you remember the Reed Spacers of the time (although those are still sold....

fun times...

HR

[ickfinger]

so does anyone have a liquid cooled 125 or 250 with yeis?

[82it465]

Yamaha Energy Induction System !!! Good Stuff, My 82 465 has it, first year, 81s did not have this setup, Was supposed to widen and smooth out the Power band, must work, the 465 has power from nothing to the very top !!!

[Hawaii-Rider]

Sorry for the miss....

no

the J model YZs, 125 and the 250 water pumpers did NOT have the YEIS system, but the air cooled 490 did come stock with them.

HR

What gives? I know what it does, how its mounted, etc. But how come I find articles referring to it on 82 yz's My 82 125 doesnt have it, but in Daves tests and ariticles home page, it shows a 125 without it while stating it's on there. There's also a picture further down the page of an 82 250 with and without it! I know my 82 490 had it because I can remember moving it out of the way every time I needed to replace the plug(frequently). What gives? Is my bike missing it?

[ickfinger]

thank you hawaiirider, before you nobody answered my question. This drove me nuts as I did see" 82 yz125" intake manifolds with fitting for yeis:thumbsup: I'm guessing pics and article might have been pre-production.

[Helmet_Hair]

My understanding of the YEIS was that it was only on the air-cooled, non-power valved IT's and YZ's. I don't think I'd seen them on the liquid cooled bikes...but I'd heard some MX guys continued to run them on their early liquid cooled YZ's.

I answered your question in my first sentence.

[ickfinger]

as far as yeis being only on air cooled yz's, I'm almost certain 82 yz 80's had it, and they were wet bikes

[YZEtc]

as far as yeis being only on air cooled yz's, I'm almost certain 82 yz 80's had it, and they were wet bikes

That's true.

The YZ-80J had this.

In later years, other models that weren't YZs used it, too, but they didn't bother to stick the plastic canister out in the open and put a YEIS sticker on it.

My 1990 Yamaha DT-200RA (a liquid-cooled dual-purpose bike that I bought in Canada) used it, and the plastic canister just sat right on top of the rubber inlet manifold.