Cylinder Intake pipe vacuum hose?

[Oldnick]

My 1998 1500 (Australia) has a vacuum hose that goes from the rear left carby and appears to go to a little push switch, presumably vacuum operated,  on the right side, under the side panel. What is that switch for? It has three wires going from it and has a red body about 1/2' cubed. The switch is in a mess, or at least there is some sort of rubber fitting on it that is a mess and I need to know if I need to buy a new one. That could take some time as the local guys do not carry much Valk stuff.

I am working on getting the trike rego'd (still dammit!) and need to know if this is some sort of pollution thing. My manual does not even mention the vacuum line when taking the carbies off, so finding the switch itself would be like a needle in a haystack.

I noticed that the engine had developed a lost pot at idle, starting to pop and spit at about 2500 rpm under no load. Throttle reponse was fine with heavier throttle. So, I thinks, carby sync, blocked idle jet. Wait for it! So I removed the left rfear plug lead and by chance it was the one that was missin; no change in idle behaviour with no plug lead. So my next thought was blocked jet. So I started to take the bowl off the LR carby. And noticed that there was an air line coming from the intake pipe for that carb; I had to remove it to take off the carb bowl. Wait for it! So AFTER I had taken off the carb bowl and checked the jet, I noticed that lines on all other carbs were plugged, and I thought "OH yeah...or an airleak on the intake! D'Oh". Anyway I  checked the jet and cleaned the bowl (hey I had to do _something_ , even though I did not need to )

So anyway I traced the air line and found a little switch which was placed just right for the end of the line.

Thanks for any help


Nick

[Michvalk]

I can't recall ever seeing anything like what you are describing. Maybe an aftermarket part, like part of a cruise control, or something like that. Maybe someone knows something different, but, a picture of the switch would help maybe some

[Oldnick]

I can't recall ever seeing anything like what you are describing. Maybe an aftermarket part, like part of a cruise control, or something like that. Maybe someone knows something different, but, a picture of the switch would help maybe some

Thanks for the reply and sorry.

HAH! I was talking turkey snot  . It's the vacuum line to the tank. The switch is just that, a switch. The vacuum line just happeden to have fallen right next to it.

I took the tank off and found where the hose goes. But as with all this stuff it is JUST long enouygh and a pain to fit. So smarty here decides to remove the carby end and worry about it later, except when I went around to the LHS to put it back it has disappeared into the guts of the engine.  I am getting good at taking off the tank.

Nick

[The emperor has no clothes]

I can't recall ever seeing anything like what you are describing. Maybe an aftermarket part, like part of a cruise control, or something like that. Maybe someone knows something different, but, a picture of the switch would help maybe some

Thanks for the reply and sorry.

HAH! I was talking turkey snot  . It's the vacuum line to the tank. The switch is just that, a switch. The vacuum line just happeden to have fallen right next to it.

I took the tank off and found where the hose goes. But as with all this stuff it is JUST long enouygh and a pain to fit. So smarty here decides to remove the carby end and worry about it later, except when I went around to the LHS to put it back it has disappeared into the guts of the engine.  I am getting good at taking off the tank.

Nick

Youll need to leave that connected. It's what allows gas to flow out of the petcock to the carbs. Replacing with a new one is a good idea.

[Oldnick]

Yah once I stopped faffing about with switches and realised where it went I knew what it was for, but thanks for the heeds-up. That's why I have to take off the dang tank and find the intake end again 

Nick

[The emperor has no clothes]

Yah once I stopped faffing about with switches and realised where it went I knew what it was for, but thanks for the heeds-up. That's why I have to take off the dang tank and find the intake end again 

Nick

You don`t need to remove it. Just raise the back up a bit. It`s on the petcock. 

[Oldnick]

I am going to try that, but it's other end that has disappeared down into the guts. Trouble is, being vacuum hose it is pretty stiff and iut may well noit be easily extractable. We shall see.

Nick

[John Schmidt]

If it's stiff then it needs replacing. And the routing of that hose isn't all that critical, as long as it reaches the two points intended you can dress it any way that's convenient.

[Oldnick]

hmmm...yeah maybe it does, but I reckon it's a replacement already, because it's a shiny stiff plastic and not rubber like all the others.

Actually just about all the hoses above the crankcase need replacing; probably the heat in there. Gunna be a pain of a job. Some of them are so fiddly. I cut some split ends and reconnected, just to try to get through rego without even _more_ fiddling. There are no splits or cracks in the hoses, except where they are stretched onto the nipples that take them.

I am not surprised. It's a what, 17 yo, 200,000Km bike? Even the trike mod is 10 yo.

Nick

[pais]

hmmm...yeah maybe it does, but I reckon it's a replacement already, because it's a shiny stiff plastic and not rubber like all the others.

If you are speaking of your fuel hose. That shiny plastic sleeve that covers said hose. I believe is stock and is there to protect it as it sits on rear metal carb stay.

[Oldnick]

No it's the vaccum line from the rear cylinder intake, LHS, to the petcock. My fuel lines are replacements, because the trike has an external fuel tank that is plumbed in to the main fuel tank. Rubber fuel lines only.

Nick

[Blackduck]

Nick,
Would you like me to come up and have an eyeball?
I have had the carb's off several times and know my way around the plumbing.
Cheers Steve

[Oldnick]

Thanks Steve, but it's sorted. The Valk is on the road (not rego'd but on the road). I am rather familiar with the damn plumbing myself by now . But I do appreciate the offer, because it is very complex.

The trike has added problems; there is an external fuel tank in the top box, which is plumbed into the main fuel system.  Somore pipes inder the tank. Then there is a panel at the LHS, right in front of the LHS side cover, which has switches for the remote fuel tank, an air bag suspension setup, and a reverse drive. More blanking panels, more wires.

So I have more pipes and more wires in an already crowded space. Many of the hoses are old and keep falling off. I have, I hope now got them all secure, but need replacing.

Rode the girl on the back roads today. Grunt and a bit scary to an old biker.

Nick