Vacuum to manual petcock conversion

[Fj.itis]

Hi guys,

Just wondering if anyones tried to mod the existing petcock over to manual? Im asking because I've done this to mine today due to the diaphragms leaking, haven't tried it out yet but now prime is 'on' and on is 'off'. I plugged the orifice between the tank feed and the diaphragm, then removed the diaphragms and blanked the back off and also the vacuum line out for good measure.

Has anyone done this and have any reason why it might be a bad idea?

[motohorseman]

Hi guys,

Just wondering if anyones tried to mod the existing petcock over to manual? Im asking because I've done this to mine today due to the diaphragms leaking, haven't tried it out yet but now prime is 'on' and on is 'off'. I plugged the orifice between the tank feed and the diaphragm, then removed the diaphragms and blanked the back off and also the vacuum line out for good measure.

Has anyone done this and have any reason why it might be a bad idea?

Well, I felt your pain.

I've been using a Motion Pro Part # 12-0036 - with hesitation, but I've not had any issues. in addition to the stock petock, it's still in place.



http://www.motionpro.com/motorcycle/partno/12-0036/

Here are the spec's -

Inline fuel valve, fits 5/16 inch fuel line

• Ideal for use on ATVs or other vehicles where an inline fuel petcock is necessary
• Rugged steel construction with zinc plating
• Viton 0-ring stands up to most fuels
• Not recommended for engines over 300cc

The last line is my concern. I looked through the valve, the restriction seemed minimal/nominal, and as our bikes use a fuel pump I hoped it would flow enough fuel, and so far, I've had no issues or concerns.

Remove the seat, pop the right side cover open a bit and then flip the valve open or closed.

The pictures will show my install, I can't recommend it (due to the 300cc rating and the American liability lifestyle), but it's an option, inexpensive and locally available (any dealer can order it for you).

I've long since fixed my carburetors and left that valve in place anyway, "just in case" and as added assurances when the bike is parked for extended periods of time. In prep for those times, I'll unplug the fuel pump, turn the valve to off and run the bike until it's used the fuel in the float bowls. I'll try to start it again after it dies with the choke on, do my best to run all the fuel out without allowing the bike to run too lean for any length of time. Generally, it's a quick process.

[motohorseman]

Good luck!

[Fj.itis]

That was my original idea to put an inline valve in but i decided to see if i could make the stock one into an on/off valve instead. That will definitely be my fall back if this doesn't pan out though, thanks for your help..

[Fj.itis]

Ok... So i tested it today and it works fine, exactly what i expected. Just got to keep an eye on it for a while to see if it will stand the test of time!

[Motorheaddad]

Do you have pictures or a write up?

[Fj.itis]

No pics but ill try to run through it best i can.

This is what i did and havent had any probs so far, but that doesnt mean i wont, so do it at your own peril.

1. Removed petcock

2. Undone the the diaphram cover, 5 screws i think.

3. Disgarded the plastic piece with the diaphram, spring and piston

4. Filled both holes from the diaphram side with epoxy putty made for petrol tanks, 1 hole leads from diaphram area to main tank feed the other ajoins with the feed from the tap side. I also plugged the vaccum inlet to the petcock.

5. Just for extra insurance i made a rubber gasket to go in between the cover and petcock.

6. Because i removed plastic piece 1 of the screws is to long so i filed it down.

7. Put it back together and "on" will be OFF and prime will be ON.

8. Plugged the vuccum hose at the carbs aswell so i dont suck air.


This is just the way i did it, you might be able to improve on it but this is what i had on hand and didn't cost me anything. I also had to replace the oring on the tap side as it was leaking as well.

[Pat Conlon]

The big question...how do you get to it to turn it off?

You really, really need to turn it off you know......really.

[Fj.itis]

Well you will be happy to know it does turn off.

If you have seen inside the petcock it has a main feed going straight to the diaphragm, it is that orifice and the one next to it that is plugged so when the petcock is in the "on" position fuel can no longer flow due to the hole being plugged. Also when the petcock is in the prime position fuel can only flow to the carbs, not back into the diaphragm area.

So i turn the tap off every time i park the bike and turn it back on when i go for a spin, bit of a pain but its not that difficult.

[Pat Conlon]

Thanks for the mod tips

Do you have to remove the seat and left side cover to get to petcock?
.... or do you also have to unbolt and lift the tank?

[Fj.itis]

Ummm nah, my bike is a fighter with no fairings at all. Just reach under the tank and turn it off.

I just realised thats what you were asking in the previous post, sorry i miss read it. Lol. Would prove to be a mission to reach for the guys out there with fairings, but still doable and will get you by until a new unit turns up.

[Arnie]

I still don't understand why you guys with leaky petcocks don't just put a 12V solenoid NC valve inline.
Something like $15 inc shipping from ebay and they only open when they get power.  So, you connect it to any of the switched with ignition brown wires and ground.  No need to reach under the tank.

[FJ1100mjk]

Arnie, If you know of a solenoid fuel valve that you describe, that fits under the fuel tank of the earlier gravity-fed FJ's, and that is equipped with the OEM airbox, please post a link for it.

This suggestion has been proposed in the past, but it appears that anything that has been put forth already has a space claim that does not permit its installation in the above described configuration.

There is a vacuum-operated Pingel (part number 9050-AV), that looks to be small enough that it will fit, but at +$90.00, is kind of a pricey fix, but a potential fix nonetheless.

Marty

[Arnie]

Here's one:

http://www.ebay.com/itm/12V-DC-3-8-Electric-Solenoid-Valve-Water-Gas-Diesel-/360969820788?pt=LH_DefaultDomain_0&hash=item540b7a5a74

You'll have to figure out where to locate it.