Vacuum line question.

[BlackD1114]

Ok. So, there is a vacuum line that comes off of the left side enigine cover and goes to the octopus for the fuel system. Mine has a crack in the line where it connects to the octopus. I want to replace this line but I can't get the line free from where it enters the motor. I would rather not remove the side cover but if I have to then I have no choice. Any clue where this line goes to exactly and how I can remove it? The bike is an '81 LH.

[trbig]

Why are you not wanting to remove the sidecover? 4 screws and it's off. Nothing spring loaded.. no wires attached.. no jack-in-the-boxes gonna pop out at you.

Take it off and start getting to know your bike a bit.


Tod

[foreda]

Vacuum Line

I don't know about an 81 but the vacuum line going into the left side cover on my 78 & 79 is the vacuum line going to the vacuum advance. There is a rubber grommet where the line goes into the side cover. Should not be a big deal changing.

[BlackD1114]

My biggest concern was needing to buy a gasket and having to wait longer to fire up the bike. I spent two weeks for for a carb intake boot and at that rate I might have the bike running this winter if I keep needing gather up nickel and dime parts. Oh well, I'll just pop it off and get to work. Thanks for the motivation.

[foreda]

Gasket

You should be able to get the gasket material from any auto parts house and make you're own gasket.

[oldyam80sg]

You should not be really concerned about a gasket as i believe that no oil or liquid will come out.My 99 ZRX is another story as about a tablespoon or 2 of oil spills out when you remove that cover.Yours should be dry inside.

[TopCatGr58]

Missing the forest for the trees!

Ok. So, there is a vacuum line that comes off of the left side enigine cover and goes to the octopus for the fuel system. Mine has a crack in the line where it connects to the octopus. The bike is an '81 LH.

Hey Black,

What I find funny about this thread is that there were 5 replies that talked about the sidecover, but nobody said anything to CORRECT the apparent error in the routing of THAT hose!?

That hose should NOT go to the octopus, but it connects to the little brass nipple on the #2 carb body....not the synch port of the intake boot! That carb nipple is a metered vacuum for the vacuum advance. IF it's connected to the OCTY, it'll do NOTHING. And if it's connected to one of the synch ports, it'll rattle the advance unit with overpowering pulses, and won't work right.

The OCTY should have a vacuum line going from it to the #2 intake boot synch port.

Hope you get it fired up soon!
T.C.

[oldyam80sg]

That is right TC-I swore that a mechanic that did my work years ago had put it on the sync port and i believed that was correct but the noise that comes from the advancer will drive you mad!Connect it to the proper place and be done with it!

[skids]

Hah! Good one Tod!

Why are you not wanting to remove the sidecover? 4 screws and it's off. Nothing spring loaded.. no wires attached.. no jack-in-the-boxes gonna pop out at you.

Take it off and start getting to know your bike a bit.


Tod

[trbig]

[

but nobody said anything to CORRECT the apparent error in the routing of THAT hose!?

SOME of us have a somewhat legit excuse by not knowing much about how the XS advance works... so cut SOME of us a little slack. Feel free to rag on the others though.. lol.

As stated.. go to your local auto parts store and get some rolled gasket material. Go to your local dollar store or Walmart and get a $1 paper punch. I then dip my finger in some oil and coat the gasket surface of the sidecover and press it down on the gasket material.. hold it tight and trace the outline with a pen.. including down into the screw holes. Lift the sidecover off, and trace the inside of the oil mark with the pen.. then use all your kindergarten skills and cut out the gasket. Use the paper punch for the holes.


Tod

[Ivan]

You don't need a gasket for the side cover. It just bolts on. If you look carefully, there is a place that lest any stuff in there drain out, so a gasket is going to be worthless anyway. You definitely would NOT want to seal it up, as any oil that accumulates in there will surely destroy the insulation on the wires in the ignition pick up.

TC beat me to it, but yes the vacuum line should go to ported vacuum on the #2 carb. The hose that runs the vacuum shut off valve (octy) goes to the synch port on #2, or what ever one you want to run it to, I guess.

Also, vacuum line is not interchangeable with fuel line. The fuel line on bikes looks a lot like vacuum line, so be careful. The first time you try to run fuel through vacuum line, it will get hard and dry and crack. Fuel line might work ok as vacuum line, but just don't mix them up.

[trbig]

I kind of disagree with Ivan on this one. You wouldn't want to be caught in the rain and have water being wind-driven inside the seam between the case and cover into the parts that are making the fire at the right time for your motor. Anyone ever gotten a lot of moisture under a distributer cap?

There is a weep hole at the bottom that a gasket doesn't cover up. This is to let any oil that may seep from a leaking crank bearing out.

That's just my opinion on it.. for what it's worth.

Tod

[Ivan]

Hehe,

My scoot has the two bottom bolt holes busted out. no gasket and only two bolts holding it in place. I haven't spent much time in the rain, but have been through a couple downpours, and haven't had a problem....yet.

I can see Tod's point though. I definitely wouldn't seal it up tight with silicone though.

Anyone ever successfully had their case welded up in such a situation. I have been thinking about finding a welder to renew the case and drilling and tapping a coupe new holes.

[DGXSER]

One more stinkin opinion

As to the gasket, mine has one on it. Same one that was on it when I got the bike, probably the same one was on it from the factory. Stays with the cover when ever I open it up and goes right back on nice and purty every time. So unless I am just REALLY lucky (yeah...right), no need for a new gasket no matter how you look at it.

TC....I was thinkin the same thing as I read through the thread. How did all these folks, much smarter than me I feel, miss THAT. First thing that caught my eye. Where is Prom when you need him.

[TopCatGr58]

Anyone ever successfully had their case welded up in such a situation. I have been thinking about finding a welder to renew the case and drilling and tapping a coupe new holes.

Hey Ivan,

Aluminum is a PITA to weld. That case is fairly deep. Along with the threaded nubs breaking off, how much towards the engine did it break off if at all? I was thinking that you could cut/grind a recess where the bolt holes/nubs were. Then tap a threaded hole thru the case a little farther away from the cutouts towards the engine, so you could then take a piece of aluminum that you cut into an "L", secure it to the case and drill, tap the "L" with the thread size to take the timing cover bolts, and then you would have the "L"'s to secure the case to on the bottom!? JAT?
T.C.
Borrowed photo from PU coil repair showing lower left bolt nub!