Hydrolock vacuum line question

[Medina]

I've read a ton, but haven't noticed any mods to the vacuum.
WHY run the vacuum line from the source of the problem directly to cyl #6? I mean a direct line, gravity assist into the cylinder that causes the whole cascade failure to lock and busting internals?

What if a vacuum source was routed between two cylinders, what 6 and 3?, over the top just under the frame rails, there you'd put a T, then run the line back to the vac pitot tube that works the diaphragm shut off?
or did i miss the thread/post that says it wont work?

[hubcapsc]

It is hard for gas to go down to #6 even if the petcock
is seriously screwed up, unless something mysterious
also clogs the weep hole at the bottom of the petcock 



-Mike "but then it flows full blast"

[Chrisj CMA]

I've read a ton, but haven't noticed any mods to the vacuum.
WHY run the vacuum line from the source of the problem directly to cyl #6? I mean a direct line, gravity assist into the cylinder that causes the whole cascade failure to lock and busting internals?

What if a vacuum source was routed between two cylinders, what 6 and 3?, over the top just under the frame rails, there you'd put a T, then run the line back to the vac pitot tube that works the diaphragm shut off?
or did i miss the thread/post that says it wont work?

The problem is not with the vacuum.  In the petcock itself.  Once the stage is set for a hydrolock (stuck needle valve&leaky fuel valve) you could remove all vacuum to the petcock and the big event could still happen.

[Michvalk]

There is enough fuel in the line after the petcock to cause a hydrolock. Just need a stickey float to let the fuel in to the cylinder.

[Ricky-D]

Hydrolock is not limited to the #6 cylinder only. Hydrolock can occur to any of the six cylinders.

***

[Medina]

It is hard for gas to go down to #6 even if the petcock
is seriously screwed up, unless something mysterious
also clogs the weep hole at the bottom of the petcock  



-Mike "but then it flows full blast"

its early, no coffee, been on call..what am I looking at? the vac line to 6 plugged (conversion to manual?) I converted a couple of petcocks on earlier bikes...its embarrassing getting a mile or two from where you so cooly took off...and the bike pukes to the side of the road  
How amazing would a FI conversion be on these? but I digress.

in my case, the line to 6 flooded. -on nearly an empty tank- gas/gravity/weight, then not so much.
 I figured I'd do a desmog while I'm in there Rather cathartic tearing crap out and not even looking at it, tossing it directly into the trash can. I did take apart one of the reed valves to you know, just to see what was inside, but the rest, whoosh do not pass go, directly into the garbage.

floats 'seem' fine, that and the tank continued to dribble when I took it off...AFTER servicing the petcock 4-5 weeks/3-4 tanks of gas ago...no idea yet what component, what aspect of what I did caused the failure.

[Chrisj CMA]

If you are asking about the yellow cap.  It's nothing, that's a weep hole its plugging, the weep hole is for indicating a problem

Has no other function, it is not a vacuum port

[Blackduck]

That plugged port is the drain port not the vacuum tie in.
For fuel to get into the #6 line you need both diaphragms to rupture plus the drain to be plugged or in the wrong orientation.
Honda designed these so "IF" both diaphragms failed the fuel would go out the drain instead of into the vacuum line. Would need a massive set of holes to flow enough fuel the so drain would not cope and fuel end up in the vacuum line.
Cheers Steve

[Medina]

thanks Steve, clarity set in.

Claude

on the upside, the desmog went splendidly......including the bizzare experience at Autozone where the guy could NOT look up 14mm freeze plugs if I didn't know what car they went into

[hukmut]

Take those carbs off    ONE MORE TIME   and replace the float valves!  Appearances will be deceiving!

The tiny springs that are supposed to stop fuel flow are OLD and weak.

Pardon the caps, they are to just get your attention and to emphasize the need.

Cheap insurance against the dreaded hydrolock.

IMHO.




Ride safe

[Gavin_Sons]

We just did another hydrolocked bike yesterday. Got everything back together and bike fired up. Then we noticed we had no vacuum like on the petcock. #3 cylinder is the one that locked and that makes sense because that is where the vacuum for the petcock was hooked up. The bike runs out of gas with the petcock in the off position but does not require vacuum to let gas flow. I'm assuming both diaphragms are tore but dosent explain why it will shut off unless that function actas as a manual which im assuming it does since you can turn it off goimg down the road and run out of gas. So now it's getting a new cover set or one of my 3 I have on the shelf. But it does run  we did something right.

[Ricky-D]

You can shut off the gas and the bike seemingly runs out of gas but that doesn't mean the gas will not still be dripping. The only true way to check if the gas is truly stopped is to remove the gas line and observe the petcock.

It takes but a few drops a minute to be able to initiate a "hydrolock" situation.

***

[hubcapsc]

You can shut off the gas and the bike seemingly runs out of gas but that doesn't mean the gas will not still be dripping. The only true way to check if the gas is truly stopped is to remove the gas line and observe the petcock.

It takes but a few drops a minute to be able to initiate a "hydrolock" situation.

***

This same idea makes me think you should be able to remove
the intake runners, and look for drips to see which carburetors,
if any, were leaking through...

-Mike