octopus vacuum

[dodjh]

I have a 82 XJ 1100 with 4 position petcock---should there be vacuum on the vacuum line,(from under tank to octopus) if I turn the motor over and hold my thumb on the disconnected vacuum line to the octopus?
I'm not gettring fuel to a couple carbs and my in line fuel filters are not plugged. Fire is fine, tank has had fuel additive with each fill up and bike was not cranked a few months due to running the battery down in the cold weather.
The only thing I can come up with is this vacuum question or the octopus diaphragm might be plugged.

dodjh

[bikerphil]

See if the engine runs OK with the petcocks in the prime position. This bypasses the octy. If it runs, check your vac hose from the carb boot to the octy. If this checks out OK, the octy diaphram isn't working correctly. The octy can be either rebuilt or eliminated all together. If it is eliminated, you will have to remember to turn off both petcocks when you're thru riding.

[CatatonicBug]

If the Octy is working properly, it's an "all or nothing" device. It either shuts off ALL the fuel, or NONE of it. If it's letting SOME through, it sounds like the diaphragm is leaking. Sounds like a rebuild kit is in order. The kits usually come with the parts to rebuild both petcocks AND the octy. I think it's a good idea to do it all at once anyway, so you know they're all good.

[DGXSER]

Interestingly, I have checked my Octy (which I removed some months ago). It leaked so I sealed it up with gasket sealant. I find that with no vacuum applied I can blow in one side and it leaks by the diaphram, but the other side seals perfectly. So I am sure it could work that way on the bike as well.

[cueball]

Remove octoobject, throw over left shoulder, block vacuum lines, get two on / off / reserve taps and adapter plates from partsnmore.com, (they"re back) no more problems.

[John]

You don't even need new petcocks. Keep the originals, and just block off the prime port, that would be the one closest to the front of the bike. The petcocks will flow, without vacuum, in either Run or Reserve. All you need to do is remember to turn the fuel off when the bike will be sitting for a while, and don't forget to turn them back on.

[DGXSER]

and don't forget to turn them back on.

Trust me, if you do forget, the engine will remind you. In my experience, it is much easier to forget to turn them back on than to forget to turn them off.