News:

         
Welcome to FJowners.com


It is the members who make this best place for FJ related content on the internet.

Main Menu

Leaky floats - fuel shutoff

Started by Waiex191, September 25, 2021, 10:27:31 AM

Previous topic - Next topic

Waiex191

Hey guys,
My FJ has been starting poorly when cold lately.  It's been hard to figure out the right choke setting, and it's been running crappy for 20 seconds or so.  This morning I got a text from my kid that there was a puddle of gas under the bike.  So I think a float valve is leaking, or maybe more than one.  If you remember I replaced the fuel pump with a Holley, however it would appear it does not shut off fuel.  So, some questions:
1) Why would my reasonably new float valves be leaking? 
2) Could it be the o-ring on the float valve body?  Seems unlikely to me but you never know.
3) What is the remedy on the leaky float valve?  Replace the one bad one, or replace them all?
4) Any recommendations on a electrically actuated fuel turn-on?  I know there has been mentions of them but I'm having a hard time finding one using search.  Hopefully low power.

My 1981 GN400 has a manual shutoff, which I never shut off, and it generally has never leaked.  But it might appear the FJ is different.

Anyway I'm looking for opinions on how to proceed.  For now I have my manual inline shutoff turned off.  It's under the sidecover so not super easy to get to.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Pat Conlon

Re: Fuel pump....yes, as we have said, you need a fuel pump that holds back fuel when shut off.
Most low pressure automotive fuel pumps don't need this feature because in cars, the fuel tank is below the level of the carb thus the pumps are designed only to lift the fuel to the carb, with gravity holding back the fuel when the pump is off. On our bikes, the fuel tank is above the carbs.
However, if you want to keep your Holley pump, a fuel solenoid is a solution. Google 12 volt fuel solenoid and you will get many hits. These are normally closed so when the power is off, the solenoid is closed. Wire the solenoid to your fuel pump so they come on at the same time. I suggest a 3/8" size.

Noel has this setup on his FJ and he reports that it works fine.

Re: Float needles, yes, you must find out the cause and correct this condition. Even with the fuel solenoid, if your float needles leak, your bike will not run right.
When you replaced the float needles, did you also include new o rings on the brass float needle seats?
Did you damage these o rings when you installed the brass needle seats into the carb body?  Look at the tip of the needle and the seat, is it clean? Debris can hold the needle off the seat allowing fuel to pass.
Look at the floats, do they pivot freely on the pin?
Remove your fuel filter, cut it open, how does it look? Got a lot of crud in your fuel tank?
Find out which carbs are leaking. Go from there.

We have some guidance on leaking carbs in our Files section.
http://www.fjowners.com/index.php?topic=46.0

You know not to store your FJ with fuel containing E10, correct?
https://samscycle.net/storage-warning-local-gas
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

red

Waiex191,

If your fuel pump does not shut off the fuel flow, it would be good to replace it with one that does.
Check that the oil level in the crankcase has not increased (meaning that gasoline got into the oil, and wrecked the oil).  The crankcase should not smell of gasoline at the oil filler hole; if so, change the oil before running the engine.

You can find 12V solenoid valves for the fuel line on the Internet.  They typically need only a little power.  You can tap switched 12Vdc easily form almost any heavy-rated fuse in the fuse box, using a Fuse Tap from the auto-parts stores.

Unless you have crud in the fuel lines beyond the fuel filter, one bad float valve assembly for me would mean that it's time for a new set of four.  Carbs are the wrong place to pinch pennies.

Check gaskets for leaks using an aerosol spray can of body powder.  The white powder will show leaks better and sooner than any other way I know.

HTH.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Waiex191

QuoteWhen you replaced the float needles, did you also include new o rings on the brass float needle seats?
I bought the RPM carb kit with all the o-rings.  I cleaned up my seats (or Pete's seats?) and used new O rings.  I also bought 4 new needles.

QuoteDid you damage these o rings when you installed the brass needle seats into the carb body?  Look at the tip of the needle and the seat, is it clean? Debris can hold the needle off the seat allowing fuel to pass.
I don't think so.  I'll have to check the tip of the needle when I get it apart.

QuoteLook at the floats, do they pivot freely on the pin?
They absolutely did when I did the carbs.

QuoteRemove your fuel filter, cut it open, how does it look? Got a lot of crud in your fuel tank?
Cutting apart the filter will come later, but my tank is pretty clean.

QuoteYou know not to store your FJ with fuel containing E10, correct?
I've been running alcohol free gas for a while.  I have burned some E10, but that was last year.

QuoteCheck that the oil level in the crankcase has not increased (meaning that gasoline got into the oil, and wrecked the oil).
I'll check, thanks.  I know exactly what the level is because I changed the oil last Thursday. 

QuoteUnless you have crud in the fuel lines beyond the fuel filter, one bad float valve assembly for me would mean that it's time for a new set of four.  Carbs are the wrong place to pinch pennies.
I agree, which is why I bought the new parts when I got it going again.

Thanks guys, I appreciate the discussion.  I'll check out the stuff in the files section.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Reloader

Marc
1992 FJ
1999 C5
1999 911
2006 LR3

Waiex191

Quote from: Reloader on September 29, 2021, 04:16:21 PM
Here is the shut off I am using even though I do not have any leakage issues:

https://www.amazon.com/dp/B00EP1N39A/?coliid=I3FN0BIA3AHWOG&colid=1MHWZAYB2FYSW&psc=1&ref_=lv_ov_lig_dp_it
Any idea how many amps it pulls?  I wonder if splicing it to the fuel pump power would be a good implementation.

It says that the ID is 0.156", I think our fuel line is 0.25" ID.  No issues?

Thanks for the reply.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Old Rider

I would try to blow air into the fuelhose with your mouth if its possible to blow into the hose a float is set too high

Old Rider

I have to correct a little i meant with my mouth not your and if it is possible to blow into hose the float is set to low not shutting off the fuel  :bye2:

Old Rider

I forgot another tip if it is debris holding the valve open sometimes you can free it by either opening the bowl drainscrew so the valve fully opens or disconnect the fuel hose and let the bike run out of fuel so the float sinks and valve opens fully

Waiex191

Quote from: Old Rider on September 30, 2021, 05:48:40 AM
I forgot another tip if it is debris holding the valve open sometimes you can free it by either opening the bowl drainscrew so the valve fully opens or disconnect the fuel hose and let the bike run out of fuel so the float sinks and valve opens fully
I have a manual fuel shutoff. I unplugged the fuel pump, turned off the shutoff, and ran it dry. Much easier!
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

ribbert

Quote from: Waiex191 on September 29, 2021, 04:56:27 PM
Quote from: Reloader on September 29, 2021, 04:16:21 PM
Here is the shut off I am using even though I do not have any leakage issues:

https://www.amazon.com/dp/B00EP1N39A/?coliid=I3FN0BIA3AHWOG&colid=1MHWZAYB2FYSW&psc=1&ref_=lv_ov_lig_dp_it
Any idea how many amps it pulls?  I wonder if splicing it to the fuel pump power would be a good implementation.

Thanks for the reply.

Brian, I would choose a different switched power source (anything that is live with ignition). The standard fuel pump power takes a circuitous route through several other components and is not constant (it times out and can even switch off). There are plenty of alternatives.
I have everything running from relays so I've just tapped into a switched one of those. The amps they pull are negligible.

Reloader, good to see you adding this, it's a great safeguard. I notice the link says they are currently out of stock, if you haven't bought one yet you might want to consider getting one with a manual override (below) in the event of a failure. The default position when not energised is closed, the arrowed nut allows you to open it manually if need be (or just plant a piece of hose on the bike with a barb in each end to by pass it)







I have a thing about isolating vibration, I made the rubber mounted bracket. This has been fitted for more miles than most bikes here will ever do, I literally never even think about it unless the subject comes up here. It cost less than $30.

There is no good place to have a crankcase full of fuel but I have a love of riding alone in remote places where an event such as this would be disastrous, but, it's an easy risk to eliminate.




Pat, if a tank tap, hose, filter, cut-off solenoid, pump (on) line fittings, barbs and inlets all have the same ID, which one will starve the engine of fuel?

Noel



                             




"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Old Rider

    I have read your Bryan's 1989 FJ1200 rebirth in Poplar Grove, IL http://www.fjowners.com/index.php?topic=19343.0 before but,not read tru the hole tread again .You made bowl gaskets from phenolic maybe they have swelled or been distorted so that the float rubs on it and hang up.Or did you later inserted new gaskets? I had some bad quality gasket once that made the side of the float rub/hang

Reloader

Quote from: Waiex191 on September 29, 2021, 04:56:27 PM
Quote from: Reloader on September 29, 2021, 04:16:21 PM
Here is the shut off I am using even though I do not have any leakage issues:

https://www.amazon.com/dp/B00EP1N39A/?coliid=I3FN0BIA3AHWOG&colid=1MHWZAYB2FYSW&psc=1&ref_=lv_ov_lig_dp_it
Any idea how many amps it pulls?  I wonder if splicing it to the fuel pump power would be a good implementation.

It says that the ID is 0.156", I think our fuel line is 0.25" ID.  No issues?

Thanks for the reply.

Here are the specs on this valve:

Rated working pressure 0-30 PSI.
2-way normally closed inline solenoid.
Orifice size .156″ for adequate flow of all fuels.
100,000 cycle tested. Extensive test data available.
Minimum draw – only .75 amp, 12 VDC when fully energized.
1/8″ female pipe threads, inlet and outlet.
Ambient temperature rating -40°F to +250°F, or 170° Fluid.
Heavy duty construction, corrosion resistant – solid brass and plated steel.
Rated for use with gasoline, diesel fuel, air, and other media.

I tapped the on position ignition switch wire for power. Valve came with 1/4" barbs and no flow issues.
Marc
1992 FJ
1999 C5
1999 911
2006 LR3

Waiex191

Quote from: Old Rider on September 30, 2021, 09:46:23 AM
   I have read your Bryan's 1989 FJ1200 rebirth in Poplar Grove, IL http://www.fjowners.com/index.php?topic=19343.0 before but,not read tru the hole tread again .You made bowl gaskets from phenolic maybe they have swelled or been distorted so that the float rubs on it and hang up.Or did you later inserted new gaskets? I had some bad quality gasket once that made the side of the float rub/hang

I used phenolic to make a tool to make gaskets.
Quote from: Waiex191 on May 18, 2020, 12:07:08 AM
Thanks Steve, that looks like a great option if my fix is not good.

I figure that I'll probably have these carbs apart more than once.  I know I did on my GN400, but that is only one cylinder/carb.  So I thought I'd make some tooling for bowl gaskets.

Here I've drilled the big hole from the bowl protrusion (no idea what it is called or what it is for) and I am match drilling the 4 holes for the bowl screws.  The material is phenolic, maybe 1/2" thick or so.


Next I've screwed down  the tool through 3 pieces of gasket paper (forgot the 4th) into scrap plywood and am transferring holes. 


Trimming around the outside of the tool.


Marking the inside cutout.  After making my first gasket I went back and located six 1/4" holes in the inside corners of the cutout.


Fit on the bowl:


Fit on the carb body.


Also I found my original factory shop manual this morning.

Here is what I used for the gasket material.
Quote from: Waiex191 on May 18, 2020, 08:21:51 AM
Noel,
I'm using Fel-Pro 3157.  It's about 1/32" thick, or about 0.8mm.
https://www.amazon.com/3157-Fel-Pro-3157-material-para-juntas/dp/B000CNISM2/ref=sr_1_1?dchild=1&keywords=felpro%2B3157&qid=1589807650&sr=8-1&th=1

Most of my old gaskets did not survive taking the bowls off after a 16 year nap.  And I can attest that they are rock-hard. 

When I did my GN400 carb (several times) I used Fel-Pro 3045.  That worked ok but it seemed to soak up some gas.  The 3157 is rubber fiber based and should be better in this application.

I'll check when I get them apart, but I suspect they are ok.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Waiex191

So, I've still got this issue.  I had my carbs apart over the weekend as a couple of my idle jets were clogged up.  I checked all the float valves and everything was clean and good.  With the carbs inverted, I could not blow air through the fuel supply hose.  But the bike didn't want to start after sitting 11 hours at work, with the fuel shutoff left on as a test.  On the second try, when I pushed the choke off, it lit off and ran crappy for a bit.  Then it was fine.  I've got an inquiry into Holley to see if this fuel pump will shut off fuel when powered down:
https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/carbureted_fuel_pumps/carbureted_electric_fuel_pumps/parts/42S

The one I bought, the 12426, says it does not shut off the fuel.  It would be easiest if I could just swap out the pump.  If not, I'm going to buy the one Reloader mentioned and give it a try.

The insides of my carbs, and the gaskets etc all looked great. 
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL