Hydrolock

[calcruiser]

I've been digging through old threads some on the issue and can't find the answer.   Question I have is how is it possible with the stock vacuum operated petcock?  Is this problem only on valks with a gravity petcock swapped in?  Or is it the gas already in the fuel line that gets in the cylinder and that's enough to lock it up? 

[da prez]

  The fuel is leaking thru the carbs.  Usually on the left side as it is the parking lean. Petcock may or may not be faulty. The carb float needle is not sealing.  It does not take a lot of fuel to hydro-lock. Liquid will not compress. 
  Petcock ,disconnect the fuel line. In on position , no fuel should run. If it does , faulty . Apply vacuum ,fuel should flow. Release vacuum fuel should stop.
  When I buy a bike that has been sitting , I remove front center cover and ratchet wrench the engine over at least three full turns. If it will not turn , spark plugs come out. Turn over by hand a few turns and then try the starter. I put a towel over the plug holes as fuel will shoot a long way.

                                                 da prez

[DIGGER]

I trailered 280 miles to my sons ranch last summer.  When i got there the Valkyrie was hydro locked. Pulled the plugs and hit the starter.  I didnt know about the gas shooting a long ways and got a load of high speed gasoline right in the eyes.  I was by myself and blinded with very murky vision and pain and literally crawled inside and flushed my eyes and face for a long time.  The rest of the weekend my eyes were scratchy and sun sensative.  When I got home I went next morning to my eye doctor and got his blessings that my eyes should be ok in a few days.  Close call. 

[98valk]

this is from Rider mag sept 1988 about the '88 goldwing Gl1500.
they had the hydro-lock problem and it turned out to be the bowl vent hose was sagging. "the low spotfills with gas and prevents air circulation, much like a sink trap. without a connection to atmosphere, the float bowls pressurize and raw fuel is forced up and out of the carbs through the needle jet. From there gravity takes the fuel down the intake runners. if that cylinder has an open intake valve, hydrolock." "The article states that honda issued a Product Update kit on a fix in feb of that yr which included a metal air-vent pipe which kept the vent hose from sagging and a vacuum fuel valve."

Looking at the service manual pics in the carb section it shows the vent hoses as straight sections just laying loosely on top of other hoses. My 98's vent hoses have a 90 degree end. the end is installed into holes in the rear carb support frame.
or the bowl vent and overflow tubes have critters nesting inside blocking airflow.

[Hook#3287]

I trailered 280 miles to my sons ranch last summer.  When i got there the Valkyrie was hydro locked. Pulled the plugs and hit the starter.  I didnt know about the gas shooting a long ways and got a load of high speed gasoline right in the eyes.  I was by myself and blinded with very murky vision and pain and literally crawled inside and flushed my eyes and face for a long time.  The rest of the weekend my eyes were scratchy and sun sensative.  When I got home I went next morning to my eye doctor and got his blessings that my eyes should be ok in a few days.  Close call. 

Very similar to what happened to me.  Trailered to FL, unloaded and went to lunch, no issues. Came out after and hydro locked.

Pulled the plugs, hit the starter, and covered my buddy. Luckily, the only real damage to my buddy was his shirt and pants getting gas soaked.

Still, he wasn't happy.

The debate goes on if there is enough gas in the line south of the petcock to cause a lock. 

I feel there maybe, but the petcock vacuum and the carb float jet systems need to be compromised, along with the intake value in the open position.

I try to remember to do a slight starter button first, quick half second push, but don't always do it.

[calcruiser]

All excellent replies, thanks guys.  I replaced petcocks on both my bikes with new oem, for some reason they are cheap and abundant, like $30 cheap.  Changing petcock made "Lorenzo" run way better.  My thinking was this problem was from a bad diaphragm in the petcock.  Thanks to this thread, i'm going to pull plugs if ever trailering before starting with a towel over the plug holes.  I really don't want this problem, never had it and hope never will.  Gonna try and get in the habit of the soft quick starter button push test.

Off topic.  I've noticed the market changing on Valks in Cali.  Just in the last year or so.  They don't last.  Prices are up too.  They sell fast here, and there's way fewer coming up.  Hang on to your Valks boys, they are gonna get hard to replace.  Cali is gonna gobble them up.

[Mooskee]

I get questions often about hydrolock, petcocks, and using a fuel solenoid.
I wrote the linked article to address the following issues:

•   What is hydrolock?
•   Petcocks.
•   There is a failure mode of the vacuum operated petcock that can flood the #6 cylinder.
•   Why Manual Petcock?
•   Some Manual Petcock Options.
•   Fuel Shutoff Solenoid with Relay Harness.
•   Modifying the OEM Petcock to remove the Vacuum Function.

Here is a link to the article. The article is also available for download on my website.
https://img1.wsimg.com/blobby/go/70754328-6fc6-422f-89c5-60bb891503fe/downloads/548298ba-75fb-41de-ae59-189312a6fb7b/Hydrolock%2C%20Petcocks%2C%20and%20the%20Fuel%20Solenoid.pdf?ver=1774375300231

[Pluggy]

Mooksie, we know a Valkyrie stock valve is a manual valve and a vacuum valve combined into one housing.  If an owner always turns that dual valve to "OFF", would that be just as reliable as turning the Honda manual-only valve to "OFF"?

A 1998 Owners Manual says set the selector to "OFF" only for stoage.  The 2003 manual says to turn the selector to "OFF" whenever the motor is off.  Maybe Honda learned something. 

[Mooskee]

Mooksie, we know a Valkyrie stock valve is a manual valve and a vacuum valve combined into one housing.  If an owner always turns that dual valve to "OFF", would that be just as reliable as turning the Honda manual-only valve to "OFF"?

A 1998 Owners Manual says set the selector to "OFF" only for stoage.  The 2003 manual says to turn the selector to "OFF" whenever the motor is off.  Maybe Honda learned something. 

My understanding is if you eliminate the vacuum function by modifying the petcock as graphon rydr described, then it will function as you say. The stock one will turn off anyway, but can fail in a way that will allow fuel down the vacuum line.

The mod to to remove the vacuum function is simple. I have only done it with the petcock out of the tank however.

[ridingron]

Mooksie, we know a Valkyrie stock valve is a manual valve and a vacuum valve combined into one housing.  If an owner always turns that dual valve to "OFF", would that be just as reliable as turning the Honda manual-only valve to "OFF"?

A 1998 Owners Manual says set the selector to "OFF" only for storage.  The 2003 manual says to turn the selector to "OFF" whenever the motor is off.  Maybe Honda learned something. 

Or their lawyers said to to add it for CYA reasons.

[Willow]

Mooksie, we know a Valkyrie stock valve is a manual valve and a vacuum valve combined into one housing.  If an owner always turns that dual valve to "OFF", would that be just as reliable as turning the Honda manual-only valve to "OFF"?

A 1998 Owners Manual says set the selector to "OFF" only for stoage.  The 2003 manual says to turn the selector to "OFF" whenever the motor is off.  Maybe Honda learned something. 

My understanding is if you eliminate the vacuum function by modifying the petcock as graphon rydr described, then it will function as you say. The stock one will turn off anyway, but can fail in a way that will allow fuel down the vacuum line.

The mod to to remove the vacuum function is simple. I have only done it with the petcock out of the tank however.

Eliminating the vacuum function has no impact on the function of the "off" position of the OEM petcock. If one is uncomfortable with trusting the vacuum function one can certainly turn the setting to "off" whenever the bike sets idle.  That certainly should be done when the bike is being trailered. 

[ridingron]

If I were to trailer my bike, I would turn the fuel valve off, ride onto the trailer and run the bike until it died from lack of fuel.

[DIGGER]

If I were to trailer my bike, I would turn the fuel valve off, ride onto the trailer and run the bike until it died from lack of fuel.

Good idea

[Hook#3287]

If I were to trailer my bike, I would turn the fuel valve off, ride onto the trailer and run the bike until it died from lack of fuel.

I've considered that plan but have wondered if having the floats bouncing up and down the whole trip would effect them.

Probably not, but they were most not likely engineered with that in mind.

It does seem to be the best plan available.

[Willow]

Actually, I believe the bouncing of the supposedly still petcock puts extra force on the vacuum closed gate while the bouncing of the floats contributes to their not fulfilling their limiting function.

I normally don't trailer.

[LTD]

I had a valkyrie hydrolock on me starting it up at a honda dealer on a used bike they were trying to sell.  It was quite a shock.

[da prez]

I have not done any math. How much fuel is in one carburetor bowl. This is an interference engine.
That means  , if a timing belt breaks , piston will hit the valves. T H A T means, no spare room for unwanted liquids. The next carbs I have down I will measure the amount of fuel.
  The petcock is often blamed ,but is usually only a small contributor to the problem. The fuel float and needle is the main culprit.
  I always bar over a new to me engine before trying to start.

                                             da prez

[ridingron]

Don't forget to add the fuel in the lines after the on/off valve.

bar over = turn by wrench on front of motor?  Plugs in or out?

[calcruiser]

I guess there was a reason hydrolock was on my mind.  been chasing a popping problem lately.  was thinking it was a coil connection.  exhaust smelled like gas.   narrowed it down to left side.  pulled the airbox.  found a vacuum line disconnected on right side.  kinda weird, upper vacuum line on carb 3.   then noticed the vacuum diaphragm piston slide in carb 4 was wide open.  removed diaphragm covers.  found the long spring broken into 3 pieces.  never hyrdrolocked and i ran it like that a lot.  i use my valk like a car.  when the bike hit 210 degrees popping almost completely went away, so i got lazy about problem.  just to be safe i'm pulling the plug and putting a towel over cylinder 4 before next start.  point being i think the brand new petcock i put in before the spring broke saved me a major headache.  glad i used the push button test too while having the popping issue.  thankin my lucky stars and all you good folks.  springs on the way, partzillas got em for 4 bucks a piece.