Author Topic: How come we don't all install in-line fuel valves to block hydolock? (Read 45573 times)

Daytona_Mike · « **Reply #75 on:** February 06, 2015, 12:40:11 am »

Quote from: Bill_Heil_NM on February 05, 2015, 04:51:10 pm

I had a manual petcock conversion on my bike and you just have to train yourself to turn the thing off everytime you stop the bike. I cam from riding a BMW airhead and that was the drill. stop the bike, turn the petcocks off. simple. I don't have overflow tubes, had the bike for ten years and never had a problem. And when you disconnect the hose to take the tank off, you don't have to worry about gas dripping out. YOU CAN get in the habit of turning the petcock off.
Try riding a BMW with plastic QDs in the fuel line that will crack and spew gas all over you and the bike while riding down the road. Ughhhhhhhhhhhhh.

You are not going to like my opinion but I feel you should know. A manual petcock puts you at a much higher risk of hydrolock than an automatic vacuum operated petcock. The reason is that if an automatic petcock were to ever fail it only ever fails in a drip or small dribble mode. It will take all night to fill a cylinder.
A manual petock flows full force wide open (when it is turn on of course) and can over fill and fill a cylinder in a few seconds... the same amount of seconds it takes to start the bike up and or shut the bike off or stall or turn the engine off to speak to someone .. just a few seconds.. that is all it takes.

This is not just my opinion. We had it happen already and recently. Just purchased and very low miles and he had a manual petock and he blew the engine- hydrolocked it trying to start it up. Would you turn the petcock off when your having trouble starting the bike? I think not. He didn't either.
In this case if he had an automatic petcock he would not have hydrolocked the engine.

You more than others need overflow tubes.

Mettler1 · « **Reply #76 on:** February 06, 2015, 12:44:50 am »

I make mistakes. That's why I have overflow tubes. With an on-off petcock if you have a bad or weak float needle and you forget to turn the petcock off you will get a cyl full of fuel. Hit the starter and you have a HYDROLOCK episode.

PS have had 2 petcocks on my 1994 C10 for 20 yrs and they have not failed YET but at least with the overflow tubes I will know it if it does!

Daytona_Mike · « **Reply #77 on:** February 06, 2015, 01:00:06 am »

That is correct Mettler1 but you dont have to forget. With a manual you can remember every single time and still hydrolock . That is my point and that is what has happened before.
With overflow tubes you also know you have a leaky float valve no matter what petcock you have.
Without overflow tubes you only wonder why your gas mileage is low or poor. There are many many bikes running around with leaky float valves and many that have been hydrolocked. Most of the time the owners are not even aware because they do not have overflow tubes.

How many people have asked about poor fuel economy? I know the second my float(s) leak- I can smell it and see it. In my case all I have to do is do a WOT run and the piece of trash clears.
I keep my bike well maintained which includes replacing the auto petcock before it fails.

Mettler1 · « **Reply #78 on:** February 06, 2015, 04:04:19 am »

Quote from: Daytona_Mike on February 06, 2015, 01:00:06 am

That is correct Mettler1 but you dont have to forget. With a manual you can remember every single time and still hydrolock . That is my point and that is what has happened before.
With overflow tubes you also know you have a leaky float valve no matter what petcock you have.
Without overflow tubes you only wonder why your gas mileage is low or poor. There are many many bikes running around with leaky float valves and many that have been hydrolocked. Most of the time the owners are not even aware because they do not have overflow tubes.

How many people have asked about poor fuel economy? I know the second my float(s) leak- I can smell it and see it. In my case all I have to do is do a WOT run and the piece of trash clears.
I keep my bike well maintained which includes replacing the auto petcock before it fails.

Thanks for the add on. Had not thought of that one.

EBAD · « **Reply #79 on:** February 06, 2015, 12:06:14 pm »

When my bike is cold and I am trying to start it, I leave the petcock off. With the petcock off, I have fuel in the carbs. Enough fuel I might add, to allow me to ride 1 mile down the road. Considering a conservative 40mpg estimate, that means about 3.2 ounces of gas. There is no need to turn the petcock on if your bike won't start - at that point, fuel delivery is not the issue.

mattchewn · « **Reply #80 on:** February 06, 2015, 12:10:28 pm »

EBAD,
While that will definitely work for someone that rides very regularly. A bike that sits a lot or has simply sat for a longer time than normal may not have enough fuel left to get running on a cold start.
Matt

LessPaul · « **Reply #81 on:** February 06, 2015, 01:37:34 pm »

Is running a second on/off valve downstream from the OEM petcock an option?

EBAD · « **Reply #82 on:** February 06, 2015, 02:13:42 pm »

Yes, that is an option. I took that route as cheap hydrolock protection.

I start up the bike with the valve off, and BEFORE I hit the kill switch, I turn it back off. It is 2nd nature to me now, even if I ride my other bike on Saturday, I can ride the Connie on Sunday and still remember to hit the valve before each stop.

For a downside, if I let someone ride my bike, they may not remember to turn the gas off before they kill the engine. Luckily no one wants to ride my burgundy whale but me!

Rev Ryder · « **Reply #83 on:** February 06, 2015, 03:23:30 pm »

Quote from: mattchewn on February 06, 2015, 12:10:28 pm

EBAD,
While that will definitely work for someone that rides very regularly. A bike that sits a lot or has simply sat for a longer time than normal may not have enough fuel left to get running on a cold start.
Matt

My experience is that the bowls on a bike with overflow tubes will be dry as a bone in a day during a South Texas summer... about five days in winter. Without overflow tubes that is more than tripled. I'm amazed at how fast the fuel disappears when the bowls have flow through ventilation. Before the tubes I almost NEVER used the PRI setting, but now it is pretty much a necessity if the bike has set more than a day or two (which for me is common any more). Without overflow tubes I could easily go a week in summer without needing PRI to get started. Just saying that Matt is right, and to some degree, so is EBAD (providing he does not have overflow tubes).

SteveJ. · « **Reply #84 on:** February 06, 2015, 04:12:52 pm »

Quote from: Rev Ryder on February 06, 2015, 03:23:30 pm

Quote from: mattchewn on February 06, 2015, 12:10:28 pm
EBAD,
While that will definitely work for someone that rides very regularly. A bike that sits a lot or has simply sat for a longer time than normal may not have enough fuel left to get running on a cold start.
Matt

My experience is that the bowls on a bike with overflow tubes will be dry as a bone in a day during a South Texas summer... about five days in winter. Without overflow tubes that is more than tripled. I'm amazed at how fast the fuel disappears when the bowls have flow through ventilation. Before the tubes I almost NEVER used the PRI setting, but now it is pretty much a necessity if the bike has set more than a day or two (which for me is common any more). Without overflow tubes I could easily go a week in summer without needing PRI to get started. Just saying that Matt is right, and to some degree, so is EBAD (providing he does not have overflow tubes).

To follow up on this, would it be a good idea to just block off the factory bowl venting and just vent with the overflow tubes? Of course, one would not want to keep fluid in the p-trap in the drain line, just eliminating the p-trap.

Steve in Sunny Fla · « **Reply #85 on:** February 06, 2015, 04:23:18 pm »

Quote from: SteveJ. on February 06, 2015, 04:12:52 pm

To follow up on this, would it be a good idea to just block off the factory bowl venting and just vent with the overflow tubes? Of course, one would not want to keep fluid in the p-trap in the drain line, just eliminating the p-trap.

Probably, but I would run a test first. I know on a carb without overflow tubes, if you block the vent tube the bike will immediately shut off due to fuel starvation. I would test your theory by blocking the vents and seeing if the bike still even idled. If it did so, a ride, testing for indications of fuel starvation would be next in order. JMO, Steve

Rev Ryder · « **Reply #86 on:** February 06, 2015, 06:49:48 pm »

Quote from: Steve in Sunny Fla on February 06, 2015, 04:23:18 pm

Quote from: SteveJ. on February 06, 2015, 04:12:52 pm
To follow up on this, would it be a good idea to just block off the factory bowl venting and just vent with the overflow tubes? Of course, one would not want to keep fluid in the p-trap in the drain line, just eliminating the p-trap.

Probably, but I would run a test first. I know on a carb without overflow tubes, if you block the vent tube the bike will immediately shut off due to fuel starvation. I would test your theory by blocking the vents and seeing if the bike still even idled. If it did so, a ride, testing for indications of fuel starvation would be next in order. JMO, Steve

Steve (and Steve),
I know I haven't tried it, but I'm betting that would work just fine. We know the tubes let in plenty of air so the bike shouldn't know its original vents were plugged at all. Providing , of course, that there is no blockage in the drain tubing. I'm going to have to do this one and soon too. Maybe on Monday when I have some time.

SteveJ. · « **Reply #87 on:** February 06, 2015, 08:27:40 pm »

OK. I just plugged the top vents and went for an Italian tune up. Everything seems good.

It is now beer:30, I'm out.

JDM · « **Reply #88 on:** February 08, 2015, 12:27:35 pm »

This is starting to get very interesting. It gets the old gray matter to working so keep poking at this folks. Sounds like we might be on the verge of learning something new.

SteveJ. · « **Reply #89 on:** February 08, 2015, 02:57:23 pm »

I went on a 200 mile ride a bout yesterday in the lovely 70* temps.

I made sure, also, that there was no carbon formation in the engine internals.

The bike runs and idles perfectly. Oh, the bike turned 214k miles also.

gottaride · « **Reply #90 on:** February 08, 2015, 03:48:19 pm »

Up here in Alberta my parking spot faces south and gets above 80F with very low humidity. Same results as Rev for overflow bowls draining within a day or two of not starting. To start I rotate my manual petcock 90 degrees to on then activate prime for a 20 count then switch to on. The manual petcock is brass and quite small. So glad it's there.

I overlooked mentioning that on tours I get paranoid about hydrolock and use the manual valve all the time. I just don't trust that OEM petcock despite it's being new. I should probably convert it to manual and be done with it. Let's face it the stock petcock is unreliable.

Big E · « **Reply #91 on:** February 08, 2015, 07:23:13 pm »

I did the same EBAD I just put another shut off downstream of the factory shut off as a precaution. You don't have to shut it off every time you stop ..... Its going to take a while to fill a cylinder to hydrolock it. I shut it off overnight and whule in storage over the winter. Then I check the factory petcock once a monthe or so and all is well .....

Steve in Sunny Fla · « **Reply #92 on:** February 08, 2015, 08:41:39 pm »

...until y'all find out it's starving the carbs for fuel... ??? Steve

gottaride · « **Reply #93 on:** February 08, 2015, 09:55:47 pm »

That"s bull in my case, it's the same I.D. as the fuel line. Folks said the same thing about the Napa3006 fuel filter and that's bull too. Just sayin'. Never once had any difficulty with WOT up to 120mph fully loaded for bear touring.
Steve in this singular case you are not correct.

Thud300 · « **Reply #94 on:** February 08, 2015, 10:15:11 pm »

For a hydrolock to occur, it would only take enough fuel to fill a cylinder to just before TDC..... curious, does anyone know what that volume is?

Mcfly · « **Reply #95 on:** February 08, 2015, 10:41:10 pm »

Quote from: Thud300 on February 08, 2015, 10:15:11 pm

For a hydrolock to occur, it would only take enough fuel to fill a cylinder to just before TDC..... curious, does anyone know what that volume is?

1 liter.... 4 cylinders... 250 ml would be actual displacement of a cylinder from bottom to top of the stroke, which is a hair under 8.5 ounces.
I'm sure less than that is required... probably less than 1/2 that... my guess.

mattchewn · « **Reply #96 on:** February 08, 2015, 11:16:42 pm »

McFly,
What is the compression ratio of a ZG 1000? 10 to 1? If so it would only take slightly more than 1/10th of the compressed volume of one cylinder to have a hydrolock. The cylinder only has to have more fuel than room. Depending on piston location in the stroke that could be minimal.
Matt

Thud300 · « **Reply #97 on:** February 08, 2015, 11:41:56 pm »

By that reckoning, assuming a 10:1 ratio, the volume of a single cylinder at TDC is just under 25 cc's... so I guess 30 cc's would do it handily

Steve in Sunny Fla · « **Reply #98 on:** February 09, 2015, 03:29:35 am »

Quote from: gottaride on February 08, 2015, 09:55:47 pm

That"s bull in my case, it's the same I.D. as the fuel line. Folks said the same thing about the Napa3006 fuel filter and that's bull too. Just sayin'. Never once had any difficulty with WOT up to 120mph fully loaded for bear touring.
Steve in this singular case you are not correct.

I'm sorry, but I'm really comfortable with the fuel starvation theory. It actually doesn't originate with the filter, it originates with the tank vent. the filter exacerbates it to the point that the carbs are running only partially filled. Steve

WillyP · « **Reply #99 on:** February 09, 2015, 03:56:35 am »

Quote from: Thud300 on February 08, 2015, 11:41:56 pm

By that reckoning, assuming a 10:1 ratio, the volume of a single cylinder at TDC is just under 25 cc's... so I guess 30 cc's would do it handily

Probably far less than that... remember the fuel only has to displace enough air that the stress of going past TDC is greater than the strength of the rod. If you start with 250cc of air and replace 25cc of that with liquid, that's only 10% of the cylinder, but if at TDC you only have 25cc of space, and 25cc of fuel, you still need room for the what was 225cc of air, which obviously can't be compressed to 0cc.