My opinion on HYDROLOCK issues

[Momz]

I've owned dozens of motorcycles of all makes (HD included).
But "hydrolock" has been a hot topic among Valkyrie owners, and why does this happen?

I have a 97 that has a Pingel petcock and it did hydrolock during Bike Week last year.

I had an old BSA that hydrolocked due to a dryed out cork seal in the petcock. It was an easy repair as BSA's were dry sump engines and the petcocks were repairable.

Some of my older Hondas have had both vacuum and non-vacuum petcocks and they never hydrolocked.
But since the introduction of "oxygenated" fuels like E10 and worse yet E85, there has been an increase in motorcycle related hydrolock issues.

My theory is that the vacuum operated petcocks are simply a manufacturers way of "belt and suspenders" way of reducing possible fuel related issues. But anyone that has disassembled Valk carbs has to have noticed that the float needles are rubber tipped and usually dried out. Dried float needles in my opinion are evidence of alcohol related damage. Yes rubber will deteriorate over time, but I seen Valks with less than 16K with damaged float needles and I've had float needles last for years in Triumphs, BSAs, and Nortons last for years.  

Those Brit bikes never had to use alcohol added gasoline. These Brit bikes were known to have rather quickly deteriorating rubber parts (foot peg rubber, cable seals, tank isolators, etc.). But the float needles could last far longer. Rubber technology has progressed rapidly in the last 40 years yet we see a fairly modern motorcycle with deterioration of rubber parts.

I must conclude that the petcock and float needle issues leading to hydrolock are without question due to the use of modern alcohol enriched gasolines.

I would appreciate your opinions.

[uturn]

someone on a facebook wall suggested that the real fuel issue was the split diaphram in the petcock allowing fuel to go through the vacuum line past the carb straight into the intake. i didnt keep my factory petcock long enough to even see if thats possible, but it sounds plausible. that would answer why the fuel doesnt just drain out the vent tubes if the rubber float valve doesnt seat and goes into the engine. the vent tube is a lower level than the fuel going past the float, up the jet holders, into the throat and dribble down the intake tube.

i ripped all that crap out and put in a manual.

but your point is still valid, the alcohol could be what causes the diaphram to get brittle and split.

i hate it when people blame random problems on "bad gas". all gas is bad so long as we waste perfectly good alcohol in it.

[Patrick]

Fuel-lock can occur with a properly operating petcock regardless of what others have to say and as you found out. That is, if you had the Pingle turned off when the engine locked. [ I've had it happen]
There is enough fuel in the lines to lock a cylinder [ takes far less than an ounce] if the float valve happens to leak.
And, that is THE reason for proper starting procedure. TAP that button.

[Gryphon Rider]

someone on a facebook wall suggested that the real fuel issue was the split diaphram in the petcock allowing fuel to go through the vacuum line past the carb straight into the intake. i didnt keep my factory petcock long enough to even see if thats possible, but it sounds plausible. that would answer why the fuel doesnt just drain out the vent tubes if the rubber float valve doesnt seat and goes into the engine. the vent tube is a lower level than the fuel going past the float, up the jet holders, into the throat and dribble down the intake tube.

There are a couple of reasons why this doesn't make sense:
1. A torn vacuum diaphragm (3, below) means that the vacuum operated part of the fuel valve STAYS SHUT.
2. If the fuel diaphragm (2, below) which is opened by vacuum has a hole, fuel will leak out the vent hole in the bottom of the spacer (A, below), rather than go anywhere else.

[uturn]

oh...well, i guess that explains that. thanks!

[Chaosandconfusion]

Is hydrolock an issue with all year models of Valkyries?  Does the Rune face this problem?  Does anybody know the precentage of Valkyries that get hydrolock? 

[nogrey]

Fuel-lock can occur with a properly operating petcock regardless of what others have to say and as you found out. That is, if you had the Pingle turned off when the engine locked. [ I've had it happen]
There is enough fuel in the lines to lock a cylinder [ takes far less than an ounce] if the float valve happens to leak.
And, that is THE reason for proper starting procedure. TAP that button.

That's very interesting, and makes a lot of sense. I've never had the dreaded hydrolock, and not to ever. Like many others, I always heard the theory that it was a leaky diaphragm in the factory petcock, leaking down the vacuum tube into intake #6. My problem with that theory (even though I eliminated the possibility using a pingle) was that there are two diaphragms in the factory petcock, and a weep hole between them. If the main fails, the fuel drips out the weep hole and you'd still need to have the other diaphragm failure in order to make their theory work. So, I've always had my doubts about it. The float bowl/rubber needle valve theory holds more "water" in my opinion. Good to know.

[F6Dave]

Valks are prone to hydrolock because the downdraft carbs sit above cylinders.  If the petcock and a needle valve are leaking, it is easy for fuel to find a path down the intake and into a cylinder.

More typical inline and V-twin cylinder layouts usually have sidedraft carbs that hang off the side of an intake runner.  Fuel leaking from these carbs usually finds a path over various external parts and then to the ground.  Of course, fuel injection eliminates the problem on newer engines.

I have an old BMW airhead opposed twin, with Bing sidedraft carbs that leak all the time.  However, the leaking fuel has no way to get into a cylinder unless I were to lay the bike over on its side.  So fuel just gets on my boots.

[Momz]

Fuel-lock can occur with a properly operating petcock regardless of what others have to say and as you found out. That is, if you had the Pingle turned off when the engine locked. [ I've had it happen]
There is enough fuel in the lines to lock a cylinder [ takes far less than an ounce] if the float valve happens to leak.
And, that is THE reason for proper starting procedure. TAP that button.

That's very interesting, and makes a lot of sense. I've never had the dreaded hydrolock, and not to ever. Like many others, I always heard the theory that it was a leaky diaphragm in the factory petcock, leaking down the vacuum tube into intake #6. My problem with that theory (even though I eliminated the possibility using a pingle) was that there are two diaphragms in the factory petcock, and a weep hole between them. If the main fails, the fuel drips out the weep hole and you'd still need to have the other diaphragm failure in order to make their theory work. So, I've always had my doubts about it. The float bowl/rubber needle valve theory holds more "water" in my opinion. Good to know.

I can't speak for the rest of the country, but here in MI back in 1997 when the Valkyries were introduced, "Gasahol" was not readily available.

Oxygenated fuels were made readily available here somewhere around 2000-2001. Finding pure gasoline is a rarity here in MI.

I also believe that storing a motorcycle in the north and Midwest, filling the tank with Aviation gas would prevent a host of problems related to tank rusting and rubber deterioration issues. Thus reducing the chances of "HYDRO-LOCKING".

JMH Theory.

[Blackduck]

You vcan pull a petcock and srip and see nothing wrong with the diaphragms.
My lock came from a blocked vacuum bleed hole in the petcock along with a float sticking.
Had had the carbs off and blown out all the lines with air but something still stuck a float.
Bike was on a lifter and sitting level.
Took some time to figure out why the petcock kept flowing fuel with no vacumm on the line.
The other problem is if you do not locate the petcock so the selector knob in the centre in the bracket. Side load will lift the ball off the seat in the closed position and anything holding the diaphragm of the seat will let fuel flow.
Most float needles are not natural rubber but Viton and can handle a whole range of liquids

[Patrick]

Fuel-lock can occur with a properly operating petcock regardless of what others have to say and as you found out. That is, if you had the Pingle turned off when the engine locked. [ I've had it happen]
There is enough fuel in the lines to lock a cylinder [ takes far less than an ounce] if the float valve happens to leak.
And, that is THE reason for proper starting procedure. TAP that button.

That's very interesting, and makes a lot of sense. I've never had the dreaded hydrolock, and not to ever. Like many others, I always heard the theory that it was a leaky diaphragm in the factory petcock, leaking down the vacuum tube into intake #6. My problem with that theory (even though I eliminated the possibility using a pingle) was that there are two diaphragms in the factory petcock, and a weep hole between them. If the main fails, the fuel drips out the weep hole and you'd still need to have the other diaphragm failure in order to make their theory work. So, I've always had my doubts about it. The float bowl/rubber needle valve theory holds more "water" in my opinion. Good to know.

I can't speak for the rest of the country, but here in MI back in 1997 when the Valkyries were introduced, "Gasahol" was not readily available.

Oxygenated fuels were made readily available here somewhere around 2000-2001. Finding pure gasoline is a rarity here in MI.

I also believe that storing a motorcycle in the north and Midwest, filling the tank with Aviation gas would prevent a host of problems related to tank rusting and rubber deterioration issues. Thus reducing the chances of "HYDRO-LOCKING".

JMH Theory.

It appears the key is to keep these monsters moving. The more fuel moving through these things the less likely a fuel-lock is. The higher mileage bike seem to have less issue than the bikes that sit for long periods.
I believe properly treating the fuel for any storage helps which means getting the treated fuel into the carburetors.
Our wonderful ethanol fuel is junk. Most areas have non ethanol fuel, such as marinas,etc. But, auto fuel still breaks down with time. Aviation fuel has a different hydrocarbon chain and doesn't break down which makes it good for storage, but, its over $6/gal here.