What is this vacuum hose and where does it go?
#1
09-21-2010, 02:11 PM
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What is this vacuum hose and where does it go?
1993 Honda CBR600 F2. I have the service manual and I couldn't find ANYTHING about where this dang hose goes? I know it's a vacuum hose because I started the bike and felt it pulling air. I purchased this bike used a few weeks ago and have been working on it to get it ready for spring '11... but this one has stumped me.
I also found an empty nozzle (its gold colored in the picture) on the bottom of my gas tank but according to the service manual it is actually a drain hose... the hose from the engine seems to short to reach...
I also found an empty nozzle (its gold colored in the picture) on the bottom of my gas tank but according to the service manual it is actually a drain hose... the hose from the engine seems to short to reach...
Last edited by uhhmoney; 09-21-2010 at 02:18 PM. Reason: added detail
#2
09-21-2010, 02:23 PM
Senior Member
the nozzle under your tank is a drain - it should go straight down next to the other hose in that last pic - through that same bracket and be allowed to exit under the bike somewhere safe.
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
#3
09-21-2010, 03:34 PM
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the nozzle under your tank is a drain - it should go straight down next to the other hose in that last pic - through that same bracket and be allowed to exit under the bike somewhere safe.
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
Here's the next dilemma, there doesn't seem to be ANYWHERE for the hose to connect to. There is only one nozzle on the petcock and it goes to the main fuel line. Here's a pic of the petcock... aftermarket maybe? Should I just block off the tube?
Last edited by uhhmoney; 09-21-2010 at 03:46 PM. Reason: added info
#4
09-21-2010, 04:07 PM
Senior Member
that is interesting - just need to check - but you do have an F2, correct? That petcock looks very "clean" to be as old as the bike, and there should be a second nozzle for the vacuum line. On the f2 - the vacuum line operates something in the petcock that allows the fuel to flow when the engine is running. Many of us don't turn our fuel valves off except when the bike is going to be parked for long periods, since there is an internal mechanism restricting fuel flow when the engine isn't running.
Ok- I just did a websearch - what it appears you have there is a F4 petcock that someone has modified for the F2 on/off/res selector to fit on. (that's why there's a hoseclamp on it) I personally haven't researched if that's a good idea or not, but I haven't heard of anyone doing it around here. Might search around. In this case though - the non-injected F4 still has a fuel pump. I simply don't know if that part will or won't work like you need.
If it does work properly - then that vacuum hose is now not needed, and I guess should be plugged.
Ok- I just did a websearch - what it appears you have there is a F4 petcock that someone has modified for the F2 on/off/res selector to fit on. (that's why there's a hoseclamp on it) I personally haven't researched if that's a good idea or not, but I haven't heard of anyone doing it around here. Might search around. In this case though - the non-injected F4 still has a fuel pump. I simply don't know if that part will or won't work like you need.
If it does work properly - then that vacuum hose is now not needed, and I guess should be plugged.
#6
09-21-2010, 06:20 PM
You are in the same situation I was in. You have an F3 petcock attached to your tank. At some point a PO switched out the F2 petcock, which requires a vacuum to open, with an F3 petcock which is free-flowing as soon as the fuel valve is set to ON or RESERVE. As you already figured out, all you need to do is block the vacuum line off and you're good.
#7
09-21-2010, 07:39 PM
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Posts: n/a
You are in the same situation I was in. You have an F3 petcock attached to your tank. At some point a PO switched out the F2 petcock, which requires a vacuum to open, with an F3 petcock which is free-flowing as soon as the fuel valve is set to ON or RESERVE. As you already figured out, all you need to do is block the vacuum line off and you're good.
#8
09-22-2010, 06:01 AM
the nozzle under your tank is a drain - it should go straight down next to the other hose in that last pic - through that same bracket and be allowed to exit under the bike somewhere safe.
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
The vacuum hose goes to your petcock. I'm assuming you've had the tank off the bike recently for all of these to be missing/misplaced?
#9
09-22-2010, 09:28 AM
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