SMALL VACUUM HOSE IN AIR FILTER BOX?

[Andrew]

I have started putting the 83 xz 550 I bought last week back together. There are alot of basic wire repairs and undone vacuum lines that I'm fixing/figuring out. I think I'm getting close. I just need some confirmation on where they go. One has been cut coming from one of  the boots that looks like if extended would go to the pet cock.  Is that correct? Also on the bottom of the air filter housing there are two tubes.... Do they go to the heads respectfully? Also I found a smaller one tucked inside the air box...... That's the one I can't figure out..... There looks like a port on the front carb on the right side..... Is that the place where it goes? LAST Question....are the bulbs on the cluster.... Ie the green neutral light replaceable? Haven't dug into that yet.... Just a question while I'm here. THANKS IN ADVANCE ANYONE... 😁

[pinholenz]

Hi Andrew. Is yours and '83 model or an '82 first registered in "83? If it has a fuel guage then its an '83

I only have experience on an '82 model and the carbs on the 83 are different but I think the vacuum lines etc are the same.

1. There should be a vacuum tube from the boot to the petcock. This opens the petcock to let fuel into the lines. The PRI position bypasses this
2. The big airbox tubes go to the rocker covers to draw off oil fumes.
3. The small airbox pipe goes from the flapper box through the airbox down to the front carb. This vacuum operates the flapper box.
4. The dashboard lights are replaceable but its a pig of a job. Personally I wouldnt worry about it unless you have to dismantle the instrument cluster for other reasons.....

Good luck

[Andrew]

Ok thanks... Next question there is a little black round device at the front of the front carb. It appears to have one line going to each carb... What does this do?..... I seem to have the bike running and idling well.... When I twist the throttle fast it bogs out..... I don't see any extra fuel coming from the little brass tubes when I look in the tops of the carbs at all..... Is this similar to a acceleration on a car where it dumps fuel until the carb can catch up to the acceleration? ..

[Andrew]

Oh ya it's an 83!

[The Prophet of Doom]

It should go to front carb only.  It's a filtered air breather.
Yes.  If the pump is not squirting when you whack the throttle, you either have no fuel or the accel pump diaphragm is ruptured, jets are blocked.  Blokage is the most likely, they are very tiny and block easily.


Cleaning time.