Vacuum stuff inside fairing

[slibno]

I have a 1981 XS1100 special. It is equipped as a touring bike, with hard bags, chest and the Yamaha 2-piece fairing. I'd like to take the fairing off, but it has a bunch of stuff inside it that I don't know what it is or what it does. It has a couple of vacuum looking things, with a hose that goes to the engine, and a cable that goes under the gas tank, and is no longer attached to anything. It also has something called a "compensator." Can anyone tell me what this stuff is, and if I can remove it? Also, if I remove all the touring stuff, should I adjust the suspension to account for reduced weight? Thanks.

[mro]

Hose that goes to engine?
Where connected ?

If you check in the manual, has recommendations for setting air pressure and dampening for the forks/shocks. Will depend on weight and your preference

Have an 81 special but have too many other projects and have yet to play with it.

Can check at the Yamaha site (has part catolog)can help identify parts.
click >http://www.yamaha-motor.com/sport/my...starthere.aspx


mro
Welcome to XSland,
got any pics of your bike???

[mro]

btw2
at yamaha site
do not need to sign up
click "proceed to catolog"


mro

[slibno]

The hose is attached to the intake manifold. I guess that's what it would be. I know little about cycle engines, and am translating what I know about cars. It would be between the carbs and the engine. I am guessing it is a vacuum choke that has already been disconnected. Thanks.

[mro]

On a stock special...

Only thing connected to the ports on the intake boots is the vacuum actuated fuel valve on the "octopus". The other three are capped off. On number two carb is a port for the vacuum advance hose.
Choke (enricher circut) enabled with lever on number one carb.


mro

[slibno]

What does the vacuum advance do, and where does all this stuff inside the fairing reside on a bike without the fairing?

[mro]

Vacuum advance/retard does pretty much same as on a car and helps attain better fuel economy.

Left side engine cover should have a vacuum hose coming out of it which goes to number two carb body as well as a small wiring harness from pick up coils.

Head light bucket will hold the wiring.



mro

[slibno]

This has to be the vacuum advance. the hose is attached to intake boot of the #3 carb. The actual mechanism was in the fairing, and the cable was disconnected. I removed the fairing, along with all the stuff that was in it. I can't see anywhere where the cable was attached. Should I try to figure out how to hook it back up? I don't see any of this detailed in the clymer service manual. I can't figure out where the stuff in the fairing would go if not there. It's pretty sizeable. I think the "compensator" thing was the cruise control, which I also removed.

[slibno]

now i'm thoroughly confused. I see that the vacuum advance mechanism is inside the engine housing on the left side. I have no clue what this stuff is. I'm back to thinking its some kind of vacuum actuated choke. I'm just clueless!

[slibno]

I think I just figured it out. It's all part of the cruise control!

Thanks for your help!

[mro]

Other than throttle locks have not seen any other XS "cruise control"

Would like to see a pic of the parts


mro

[renegade_xs11g]

SLIBNO..................

SLOW DOWN A SECOND...
vacuum advance does NOT reside in the fairing,
neither does the OCTY,
they have places they belong,

so the question is....IF THEY ARE IN THE FAIRING, WHY AREN'T THEY WHERE THEY BELONG.

Hopefully they are spares, but they may have been removed

do you have a digital camera...can you post pics
you really need to identify those parts

the only thing in the fairing would be lighting, maybe a radio

[TopCatGr58]

My vote is cruise control also. I've seen some fancier electronic and vacuum controlled/sensing speed controllers that would adjust the speed when it senses an increased load/vacuum on the system to help keep your speed constant when going up hills and such. I know with my regular throttle lock that my bike is hard to maintain speeds on rolling hills, slows uphill and speeds up downhill!
T.C.

[slibno]

I am certain it is cruise control. There was a small thumb wheel mounted on the mirror mast beside the left hand grip. Inside the fairing there was box with circuitry attached to the switch, plus a small cylinder with two hoses, one attached to intake #3, and one attached to the cruise actuator mechanism inside the fairing. Out of that came a throttle cable. That is what was disconnected. It all makes sense now...mystery solved. Thanks all!

[BlkMage]

If you don't want the cruise system...

...might you be willing to sell it? I commute a half hour to work, mostly on open land, and think a cuise system would be nice.