Q: about vacuum lines. 79 XS1100 SF

[mattkey12]

I think I am getting fuel into the vacuum lines.

(79 xs11 sf)

On the right side of the bike looking at the petcock head on, I have two connections coming out of the back of the petcock. I pulled the hose off of the connection on the right closer to the front of the bike which I believe is the vacuume and fuel was in the hose.

I am getting gas in my oil. I have rebuilt the petcocks because they were leaking. those are not leaking anymore. But I had to change the oil a week or two later because I had gas in the oil again.

I am trying to find out how the gas is getting in to the oil.

Its just a guess but I think the gas is going through the vacuum lines into the motor. Is that possible?

If anyone knows where I can see a diagram of the fuel and vacuum lines let me know. Just so I can see if my connection is correct.
Thanks

[red bandit]

If you have a special with both connections the same size and both pointing the same direction...They are both fuel. "t" them together then to the carbs. 1 petcock to 1-2 carb, 1 petcock to 3-4 carb.

[mattkey12]

So I dont need all the other hoses? Just T them together and run them to the carbs? What about the vacuum?

[TopCatGr58]

Hey Matt,

The Special uses gravity feed petcocks, one nipple is for PRIME, the other is for RUN! They go into the VACUUM control valve called the OCTOPUS...mounted to the top of the #2 carb, that's what all the hoses are for. The Octopus is the vacuum control=on/off instead of the petcocks!

You've ruled out the petcocks leaking by rebuilding them, but the octopus could be faulty, but more likely, it's the float needle and seat combo that's not sealing properly inside the carbs, allowing the fuel to flow, cause when the Octo can leak, the carbs should stop it, if they are not, they are at fault.

ALso, on the carbs, there are 2 sets of hoses that come from them, the lower "T" fittings are the FUEL, the upper "T" fittings are ONLY VENTS, and are to be routed and just vented, either to the vent nipples on the air box, or to a filtered cap if you're using INDY filters!

There's an Octopus fuel routing diagram in the tech tips. Also should have technique for testing it. Or you can just rip it out, and run the lines directly from petcocks to carbs, and just remember to turn the fuel OFF when parked! BUT CHECK YOUR CARBS....the floats can also get damaged, and stop floating!
T.C.

[mattkey12]

Thanks . It is starting to make sence. I think I will do without the octo and have the floats, float needles and seats checked.

I am also concerned about something else. My bike will not do over 85 mph.

At 80 mph or at 6000 rpm at any speed in any gear the bike sounds like it is starving, the tack starts jumping from 6 to 4 and back and fourth. So I back off and keep it steady.

I have heard these bikes should do 100+ pretty easy. Not that I want to go that fast I just want to know that I can.

I guess it will take some trouble shooting.

How can I check if the clutch is in good shape? I have lots of questions...

[TopCatGr58]

We have lots of answers!

Matt,

What I said before, after you readjust it, IF it still slips, then it's worn, most likely plates and or springs, or both!

Please take some time and go to the MAIN FORUM PAGE, scroll down to the TECH TIPS, and READ THEM ALL!!!! Lots of your questions will be answered there saving you and us lots of typing!!

With your bike, more specific info would be helpful, like what if any mods, intakes, exhausts, what otehr work has already been done, how long has it sat before you started to work on it.

Many things affect performance. Yes, these machines will easily get up to 100MPH+.....when properly tuned and maintained!
The Pickup Coils are notorious for failing....info in tech tips,
Carbs dirty, vacuum slides not working, etc.....info in tech tips,
hint, hint!!
T.C.

PS, I grew up in PineHills, will be visiting family in early Oct there!

[mattkey12]

Cool! I will read it. Thanks for the help. Did You go to Evans?