Author Topic: Electronic Fuel Cut Off  (Read 8077 times)

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Offline millerized

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Re: Electronic Fuel Cut Off
« Reply #25 on: August 17, 2015, 03:14:11 pm »
When I see flashing lights, I need to know I am not going to run out of fuel. :nananana:
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Offline smithr1

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Re: Electronic Fuel Cut Off
« Reply #26 on: August 17, 2015, 05:31:39 pm »
I did a post in the Wiki section below for the elct valve.
http://forum.cog-online.org/index.php?topic=32983.0

The Concourer articles I did were:

To Mod or not to Mod, in Summer 09

Fix that leak: Spring 09

PS:  I ran the valve 5 years.  I felt like I had to rebuild it after 3 I think.  The tygon was hard and the valve insides looked rough.  Other then that I never had a failure.  I do say that the chance of failure from a partial of crap getting into the valves seat area is less then the stock valve but not non existent.
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Offline danodemotoman

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Re: Electronic Fuel Cut Off
« Reply #27 on: August 17, 2015, 05:44:47 pm »
 Using an inline filter with std gravity feed  ran the carbs dry a couple times with WOT coming down Lolo Pass into MT during the Sat ride to Missoula on the Bun Cooler event.

Offline WillyP

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Re: Electronic Fuel Cut Off
« Reply #28 on: August 17, 2015, 05:52:46 pm »
Like the issue with inline filters I think some will have an issue and some won't. Might have to do with installation particulars, or it might have to do with riding style.

Sure, you can ping off the redline with a restriction. Heck, I'm pretty sure I could hit redline with the fuel line clamped completely closed. You won't be able to hold it there very long, though. I suspect those who ride the super-slab often, and at higher speeds, especial out west where highways stretch on in a straight line for miles on end will have issues. Ride two up, and/or carrying camping gear or other high loads will add to any flow issues. Or maybe it's the mountain roads that will stress this, I don't know.

Consider the factors that make some get great gas mileage and others not so great. A sudden burst of high rpm won't matter as the bowls hold a certain amount of fuel. Try to sustain that for more than a few seconds and the motor will lean out, and soon starve out.

And another factor is that some bikes seem to have better vented tanks than others. A restriction of air going in means a restriction of fuel coming out.
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Offline rickm_tx

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Re: Electronic Fuel Cut Off
« Reply #29 on: August 17, 2015, 06:56:00 pm »
I did a post in the Wiki section below for the elct valve.
http://forum.cog-online.org/index.php?topic=32983.0

The Concourer articles I did were:

To Mod or not to Mod, in Summer 09

Fix that leak: Spring 09

PS:  I ran the valve 5 years.  I felt like I had to rebuild it after 3 I think.  The tygon was hard and the valve insides looked rough.  Other then that I never had a failure.  I do say that the chance of failure from a partial of crap getting into the valves seat area is less then the stock valve but not non existent.


Great write up and very helpful - especially the photos.

Basically you have:  90 elbow -> hose -> quick connect -> hose -> fuel filter -> hose -> valve -> hose -> quick connect -> hose -> fuel rail.

That is a bit more involved than what I had in mind.  I was thinking:  petcock -> hose -> fuel filter -> hose -> valve -> hose -> fuel rail.

I am going to leave the petcock as is.
« Last Edit: August 17, 2015, 07:31:35 pm by rickm_tx »
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Offline rickm_tx

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Re: Electronic Fuel Cut Off
« Reply #30 on: August 17, 2015, 07:26:38 pm »
I can redline the bike at anytime with no issue of fuel starvation.
Cogwheel...


For arguments sake:
Figuring we get, on average, 40mpg. RPM's vary, but that's approximately 3.2oz per minute at 60pmh.
Guestimate that there's 2oz in each fuel bowl, we'll put it at 6.4oz total to make it easy to work with the number above.
There's about 2 minutes of fuel in the bowls at a reasonable 40-50mph RPM range.

1/4" line, unencumbered by any kinks, clogged screens/filters, changes in direction will flow .279 gal per minute at a 12"/2" drop+=35.7oz per minute. Drop the drop to 1" and you're down to 15.5ish oz per minute.

Now, add in any restrictions, flow interruptions (bends, kinks, smaller orifices), things get iffy. 

Using those same calcs, your 1/8th orifice will flow 3.968oz per minute without any interruptions.  Why 1/8"...I have 1/4" fuel line on mine? (check the specs on your valve) Gravity and flow don't like restrictions...like that valve, like that 1/4" "T", or 90, or even the interior dimensions of the check valve...you're probably down to 1/8 (that valve has a 1/8" ID), at most 3/16". And while that may work on a pressurized fuel system, this ain't one.

Gravity is your friend only as long as it can do it's job without interruption. Any interruptions just means it needs to start falling again, and velocity is tied to oz per minute.  While that valve 'might' work at normal cruise speeds, long bouts with Rev'itus, any other restrictions in the pipe, carb work, even less than a full tank's worth of head pressure may reduce your ability to run full out for an extended period of time. Not many of you are going to suck your carbs dry running full out for 2min, but they probably ain't gonna refill fast enough to do it again.



All this before coffee. Now, if you'll excuse me...I need to caffeinate before this type of thinking continues and someone pays me to think this way.


Don't know so much about the math involved - other than it hurts my head, but I am taking a simpler approach.   

1.  I have an existing fuel line that works just fine, so I am assuming the math for it is correct in as much as the ID is just fine.

2.  I will remove a section of the current fuel line and replace it with a mechanical pass-thru that has a comparable ID (5/16")

3.  The decline and path of the new arrangement will not deviate from the existing configuration.  I am simply replacing rubber for metal.  Nothing else changes.  Same path, same flow, no new curves or kinks.

I am simply not convinced that the fuel valve is going to reduce or restrict the current flow to the carbs.  Either way, I intend to find out, if for no other reason than my good friend Doug took the time and effort to help me resolve the threat of a hydrolock.  Basically, it is costing me nothing but my time.

As far as an electronic cut off valve not preventing a hydrolock.....

From what I understand, 2 failures have got to occur for a hydrolock condition to exist:  1) petcock does not shut off correctly, and 2) a carb float is sticking.  With the addition of an electronic cut off valve, 3 failures would have to occur.  If I am indeed that unfortunate to beat the odds and have all 3 failures occur at the same time, well you know what - I'm toast anyway.  It just wasn't in the cards, is all.

At any rate, it's going in. 

It's not that I am opposed to overflow tubes, it is more a matter of 'least resistance'.  A free prevention device installed in 2 hours has a lot less resistance (and down time) than dismantling the carb bowls, shipping them off and paying the cost of modification.

Personally, I don't want to even have to mess with this.  I don't know how much overflow tubes installed by the factory would have increased the selling price of the bike, but I am sure, now knowing the bikes reputation, no one would have objected to the extra $30-$40.  This simply was not the place to cut costs.  But, it is what it is, and no matter what, the world will continue to spin.  In the meantime, I will take measures to protect my beloved bike.

Still, I simply don't see the concern about constricted fuel flow.  Looks like a big a** hole to me - math or no math.  Coffee or no coffee....

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Offline millerized

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Re: Electronic Fuel Cut Off
« Reply #31 on: August 17, 2015, 08:03:17 pm »
From here:
Quote
http://www.afcvalves.com/mod111.html

This:
Quote
Orifice size .156” for adequate flow of all fuels

Not saying it won't work, but you're not even to 3/16th" tube size INSIDE the solenoid.

Peace of mind for the cost you have in it though, and depending on your driving style, it could easily be win/win.
You may run all day at 55 without problems, but full flow at high RPM's for extended periods of time just won't be there. You'll eventually clear out the bowls with just a trickle coming in.

(oh, this one: http://www.afcvalves.com/mod121.html might be a bit better, in either .250  or 5/16th")
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Offline ACISROC

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Re: Electronic Fuel Cut Off
« Reply #32 on: August 17, 2015, 08:44:22 pm »
From here:
Quote
http://www.afcvalves.com/mod111.html

This:
Quote
Orifice size .156” for adequate flow of all fuels

Not saying it won't work, but you're not even to 3/16th" tube size INSIDE the solenoid.

Peace of mind for the cost you have in it though, and depending on your driving style, it could easily be win/win.
You may run all day at 55 without problems, but full flow at high RPM's for extended periods of time just won't be there. You'll eventually clear out the bowls with just a trickle coming in.

(oh, this one: http://www.afcvalves.com/mod121.html might be a bit better, in either .250  or 5/16th")
 

 Millerized:
               I looked at that link. I am not going to put one on my bike but :
                                                                                                              Won't this electric valve also be a drain on the electrical system such as an extra light or C.B. radio or something , isn't it always on with the ignition in the run position? In other words, anytime the valve is open it draws juice from the battery? I am asking you because you have such a trustworthy profile pic, and are not afraid to beat a sacred cow.
                                                                                             
                                                          Thanks, Steve

Millerized is cool   :great: :great: :great:
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Offline WillyP

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Re: Electronic Fuel Cut Off
« Reply #33 on: August 17, 2015, 09:12:21 pm »
You would have to contact the manufacturer to be sure, but generally with a valve like that there is a pull down current and a hold down current, I don't see either listed.

Pull down is like starting surge for an electric motor, it only last a second or so, I wouldn't be too concerned about that. Hold down is continuous and might be half an amp to an amp, maybe an amp and a half or so.
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Offline millerized

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Re: Electronic Fuel Cut Off
« Reply #34 on: August 17, 2015, 09:16:47 pm »
Millerized:
               I looked at that link. I am not going to put one on my bike but :
                                                                                                              Won't this electric valve also be a drain on the electrical system such as an extra light or C.B. radio or something , isn't it always on with the ignition in the run position? In other words, anytime the valve is open it draws juice from the battery? I am asking you because you have such a trustworthy profile pic, and are not afraid to beat a sacred cow.
                                                                                             
                                                          Thanks, Steve
Draw should be minimal. As long as it's normally closed and only uses juice to stay open. If it's a juice to close one, well, that's gonna cause more problems.
Would this be a better profile pic? I don't 'stomp' cows in this one....
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Offline ACISROC

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Re: Electronic Fuel Cut Off
« Reply #35 on: August 17, 2015, 09:21:20 pm »
      Willy,
               I guess I can trust you too since your avatar is cool, and  after all you are an" Administrator." :rotflmao:
    I was wondering that about the electric valves. you answered my question perfectly.
                                                         
                                                                                                                       Thank you,
                                                                                                                                        Steve :beerchug:                               
                                                                                                                       
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Offline ACISROC

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Re: Electronic Fuel Cut Off
« Reply #36 on: August 17, 2015, 09:26:31 pm »
 Thanks Millerized.
                           No don't use that picture, it reminds me too much of the guy's that used to always be looking for me.  ;)   :rotflmao:
                     Sweet pic. :beerchug:
Millerized is cool  :great: :great: :great:
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Offline Jim Snyder

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Re: Electronic Fuel Cut Off
« Reply #37 on: August 18, 2015, 12:20:44 am »
There is another solution to this issue. Buy a Pingel manual fuel valve and get Steve's overflow tubes and your problems will be solved.
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Offline smithr1

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Re: Electronic Fuel Cut Off
« Reply #38 on: August 18, 2015, 02:15:25 pm »
What I would do is test it in the system by having the tank about half full and running a gallon of gas through the petcock by itself on prime.  Poor that gallon back in and do the same thing with your valve in.  If it takes more than twice as long to flow that same gallon chances are you will have a problem.  In my test setup it took 225 seconds to flow a gallon on Prime.  Several of us had problems with a smaller valve that was tried first and it took about 440 seconds.  The bigger valve I used took 240 seconds.  These times are only relative to my setup and will not reflect absolute times for you.  There is relative flow rates for a few other parts in my Summer 09 article.

Also routing of lines is very important.  IT HAS to flow all downhill.  If there is a high spot in the lines an air bubble will form there and WILL restrict flow.   Even if you work any bubbles out on install they will return.
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Offline rickm_tx

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Re: Electronic Fuel Cut Off
« Reply #39 on: August 18, 2015, 02:28:13 pm »
What I would do is test it in the system by having the tank about half full and running a gallon of gas through the petcock by itself on prime.  Poor that gallon back in and do the same thing with your valve in.  If it takes more than twice as long to flow that same gallon chances are you will have a problem.  In my test setup it took 225 seconds to flow a gallon on Prime.  Several of us had problems with a smaller valve that was tried first and it took about 440 seconds.  The bigger valve I used took 240 seconds.  These times are only relative to my setup and will not reflect absolute times for you.  There is relative flow rates for a few other parts in my Summer 09 article.

Also routing of lines is very important.  IT HAS to flow all downhill.  If there is a high spot in the lines an air bubble will form there and WILL restrict flow.   Even if you work any bubbles out on install they will return.

This is a good idea.  Thanks.
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Offline smithr1

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Re: Electronic Fuel Cut Off
« Reply #40 on: August 18, 2015, 08:23:39 pm »
I could be wrong but I think one of the wires going to the coils is hot all the time the key is on.  Unless I am forgetting I think this is what I used.
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Offline Daytona_Mike

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Re: Electronic Fuel Cut Off
« Reply #41 on: August 19, 2015, 04:16:22 am »

As far as an electronic cut off valve not preventing a hydrolock.....

From what I understand, 2 failures have got to occur for a hydrolock condition to exist:  1) petcock does not shut off correctly, and 2) a carb float is sticking.  With the addition of an electronic cut off valve, 3 failures would have to occur.  If I am indeed that unfortunate to beat the odds and have all 3 failures occur at the same time, well you know what - I'm toast anyway.  It just wasn't in the cards, is all.


You are wrong with the above statement.  If  #1 and #2 fail then #3  (electronic cut off)will do nothing to help stop the problem.  We have been here and done this a long time ago. It does not help.
Let me explain. As soon as you turn the key on (or how ever you decide to enable the  the electronic cut off) fuel will be flowing and the engine will not be running yet  and you could hydrolock (because #1 and #2 failed). We already know it only takes less than a teaspoon of fuel to lockup the piston or about  about 3 seconds. So what have you gained by adding the electronic cut off? Nothing.
Just get overflow tubes. (unless you already have them) and never ever worry again.
Overflow tubes are the ONLY way to prevent hydrolock. <----- PERIOD  end of story!!
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Offline Bill Hookman

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Re: Electronic Fuel Cut Off
« Reply #42 on: August 19, 2015, 02:44:15 pm »
I won't deny that some people have had issues with fuel flow, because I rode with Krumgrinder once when we were stopping every 15-20 minutes on the highway to wait for his bowls to refill.  But, he had all kinds of crap on his fuel line, an electric shut off, a filter, and a quick disconnect and he had it looped under the carbs and back up.  But, I can't see how the math supports a more direct fuel line creating a fuel starvation issue.  I have always run a NAPA 90 degree filter and added a manual brass "lawnmower" shut off 2 years ago and route the line in the stock position.  I am not shy on the throttle and ride highway speeds regularly and have never had a fuel starvation issue.

Maybe I'm missing something, and I'm sure you guys won't be shy about pointing it out if I am, but:

Taking Smithr1's worst case number of 440 seconds to flow 1 gallon, let's bump it up to 480 seconds to make the math easier and the flow rate even less.  That's 1 gallon every 8 minutes.  If you're doing 80 mph on the highway getting 40 mpg, that's 1 gallon every 30 minutes.  You are flowing more than 3 1/2 times more fuel than you are using.  Let's say you're riding like a banshee and getting 20 mpg, averaging 80 mph (I'd like to meet the guy who can maintain that on a C10 for any length of time), now you are using 1 gallon every 15 minutes, still flowing almost 2 times what you are using.  The only thing I think Smithr1's test may not have considered, is that the fuel rail is horizontal, but I can't believe that would slow down flow enough to cause starvation.

YMMV.
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Offline fred-houston

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Re: Electronic Fuel Cut Off
« Reply #43 on: August 19, 2015, 03:42:23 pm »
I won't deny that some people have had issues with fuel flow, because I rode with Krumgrinder once when we were stopping every 15-20 minutes on the highway to wait for his bowls to refill.  But, he had all kinds of crap on his fuel line, an electric shut off, a filter, and a quick disconnect and he had it looped under the carbs and back up.  But, I can't see how the math supports a more direct fuel line creating a fuel starvation issue.  I have always run a NAPA 90 degree filter and added a manual brass "lawnmower" shut off 2 years ago and route the line in the stock position.  I am not shy on the throttle and ride highway speeds regularly and have never had a fuel starvation issue.

Maybe I'm missing something, and I'm sure you guys won't be shy about pointing it out if I am, but:

Taking Smithr1's worst case number of 440 seconds to flow 1 gallon, let's bump it up to 480 seconds to make the math easier and the flow rate even less.  That's 1 gallon every 8 minutes.  If you're doing 80 mph on the highway getting 40 mpg, that's 1 gallon every 30 minutes.  You are flowing more than 3 1/2 times more fuel than you are using.  Let's say you're riding like a banshee and getting 20 mpg, averaging 80 mph (I'd like to meet the guy who can maintain that on a C10 for any length of time), now you are using 1 gallon every 15 minutes, still flowing almost 2 times what you are using.  The only thing I think Smithr1's test may not have considered, is that the fuel rail is horizontal, but I can't believe that would slow down flow enough to cause starvation.

YMMV.

I have done it more than once.  The speed limit on I-10 is 80mph and I have run that a number of times going out to Big Bend.  The last time I did it my mileage was 24, but I was bucking a headwind.
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Offline smithr1

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Re: Electronic Fuel Cut Off
« Reply #44 on: August 19, 2015, 03:47:15 pm »
Your math is good but you are starting with bad numbers.  The 440 seconds has nothing to do with the flow rate on the bike.  That number is only relative to my testing setup.  It can not be translated to the bike in that way.  The flow rate on the bike is very dependent on amount of gas in the tank, venting and any restriction down stream.

Your friend with all the hose length under the tank is getting air inside the lines and that is causing restriction also, along with whatever else he did to restrict it.

As fer the valve not doing any good.  Mike is somewhat correct.  If you are not hitting the starter as soon as you turn the key you are no better off.
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Offline smithr1

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Re: Electronic Fuel Cut Off
« Reply #45 on: August 19, 2015, 03:49:39 pm »
I take that back, you are still better off in that you will not dump the entire tank of gas on the ground after you go into the house even with over flow tubes.
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Offline PaulP

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Re: Electronic Fuel Cut Off
« Reply #46 on: August 19, 2015, 06:33:04 pm »
It would not be difficult to wire the relay such that it only energizes the solenoid when the starter is engaged, but latches up after that until the key is turned off. That would make it a truly 3rd level if protection. I still like the overflow tubes better though.
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Offline WillyP

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Re: Electronic Fuel Cut Off
« Reply #47 on: August 19, 2015, 11:55:30 pm »
You could also make it so the valve opens when the oil pressure light goes off... with a 'prime' button to bypass that if the bike has been sitting long enough for the fuel to evaporate from the carbs. Or use a vacuum switch. No vacuum no gas.

If you connect it to the starter as PaulP suggested, you'd still want a bypass primer switch because you would want the carbs filled before you begin cranking. You'd also have to do some testing to insure the valve pulls open properly as there is some voltage drop when cranking.

However what happens when the electric valve stays open due to debris or age related factors? Like the vacuum valve, you are still relying on a spring to close the valve when it's not open, and you have no visual, physical verification that the valve has successfully stopped fuel flow. The only advantage you gain is that the electric solenoid might have a slightly stronger spring.
« Last Edit: August 20, 2015, 12:03:46 am by WillyP »
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Offline Tour1

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Re: Electronic Fuel Cut Off
« Reply #48 on: August 24, 2015, 02:31:26 pm »
Can't resist adding some more math.
The top speed thread says Connie can do about 120 mph.
Generally speaking, wind loads go up by the square of the speed.
Twice the speed, squared, is 4 times the load.
So if Connie gets 40 mpg at 60 she might get only 10 mpg at 120.
(Aerodynamics and engine efficiency ignored, but wide open throttle for any reason like uphill fully loaded into a headwind).
10 mpg at 120 is 12 gallons per hour.
12 gallons per hour means a gallon every 5 minutes.
If the test flow "with the big valve" takes 225 seconds (3.75 minutes) it will be ok.
If the test flow "with the small valve" takes 440 seconds (7.33 minutes) you will probably not be ok (at wide open throttle for a long time).
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Offline WillyP

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Re: Electronic Fuel Cut Off
« Reply #49 on: August 24, 2015, 04:39:02 pm »
It's all moot anyway... because of this:


As far as an electronic cut off valve not preventing a hydrolock.....

From what I understand, 2 failures have got to occur for a hydrolock condition to exist:  1) petcock does not shut off correctly, and 2) a carb float is sticking.  With the addition of an electronic cut off valve, 3 failures would have to occur.  If I am indeed that unfortunate to beat the odds and have all 3 failures occur at the same time, well you know what - I'm toast anyway.  It just wasn't in the cards, is all.


You are wrong with the above statement.  If  #1 and #2 fail then #3  (electronic cut off)will do nothing to help stop the problem.  We have been here and done this a long time ago. It does not help.
Let me explain. As soon as you turn the key on (or how ever you decide to enable the  the electronic cut off) fuel will be flowing and the engine will not be running yet  and you could hydrolock (because #1 and #2 failed). We already know it only takes less than a teaspoon of fuel to lockup the piston or about  about 3 seconds. So what have you gained by adding the electronic cut off? Nothing.
Just get overflow tubes. (unless you already have them) and never ever worry again.
Overflow tubes are the ONLY way to prevent hydrolock. <----- PERIOD  end of story!!

Also, the assumption that all three have to occur at the same time is wrong. You could have both the petcock and the electric valve with a slight leak for years and never know it... because the float valves are doing their job... until one day they don't...


And yet, anyway you look at it, the electric valve is an extra measure of safety. If it doesn't starve your bike of fuel, of course.
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