SpineFrame manual fuel petcock

[Pressureangle]

While I had the tank off cleaning and sealing electrical connections, I took the opportunity to remove and service the fuel valve. Clearly everyone who has/had one knows what an inoperable nag they become, and I had to turn mine off with pliers this time. I started with the knob, I took the snap ring off and spun it down so I could lubricate the threads. I used 'Fluid Film' wax oil for that. Then unscrewed the filter tower to see inside: 

petcock

It was nasty with white scale, as expected. I used Gumout carb & choke cleaner first, with a bit of poking around with a copper wire to scrape what I could get to. When dried, I viced it and poured a little Marvel Mystery Oil in it, let it soak a few minutes then ran the valve in and out to get the oil into the operation of the pintle. 
Unexpectedly, it worked a charm and now it's smooth and as easy as I'd expect going past an o-ring or seal or whatever's inside the demon.

[Lucky Phil]

1 hour ago, Pressureangle said:

While I had the tank off cleaning and sealing electrical connections, I took the opportunity to remove and service the fuel valve. Clearly everyone who has/had one knows what an inoperable nag they become, and I had to turn mine off with pliers this time. I started with the knob, I took the snap ring off and spun it down so I could lubricate the threads. I used 'Fluid Film' wax oil for that. Then unscrewed the filter tower to see inside: 

petcock

It was nasty with white scale, as expected. I used Gumout carb & choke cleaner first, with a bit of poking around with a copper wire to scrape what I could get to. When dried, I viced it and poured a little Marvel Mystery Oil in it, let it soak a few minutes then ran the valve in and out to get the oil into the operation of the pintle. 
Unexpectedly, it worked a charm and now it's smooth and as easy as I'd expect going past an o-ring or seal or whatever's inside the demon.

It won't last. The issue is the orings swell in fuel because they are plain nitrile. I reworked a few to use Viton seals. It's the only long term solution.

Ciao 

[Pressureangle]

34 minutes ago, Lucky Phil said:

It won't last. The issue is the orings swell in fuel because they are plain nitrile. I reworked a few to use Viton seals. It's the only long term solution.

Ciao 

I knew somebody had a thread on this. I don't close it regularly, and it has never leaked; If it starts to leak I'll get into it again. The knob didn't want to come off without a fight after leaving the threads, I didn't want to risk destroying anything so went with what I could do. I'll bookmark your thread and get the proper sized o-rings into inventory if there's a measurement in the thread.

[Lucky Phil]

2 hours ago, Pressureangle said:

I knew somebody had a thread on this. I don't close it regularly, and it has never leaked; If it starts to leak I'll get into it again. The knob didn't want to come off without a fight after leaving the threads, I didn't want to risk destroying anything so went with what I could do. I'll bookmark your thread and get the proper sized o-rings into inventory if there's a measurement in the thread.

The aluminium knob is crimped around the top edge which is what provides the open stop. I carefully file off the crimp and then modify the plunger and body with a grub screw to create a new open stop which also makes the seals replaceable.

Ciao

[Pressureangle]

Lucky Phil was right, my solution was temporary. So we dive deep. 
The trick is getting the thumbwheel off, I used a jeweler's file to skim the crimped edge as I ran it up and down the threads (after taking the E-clip off so it moved easily) until it came off without damaging the threads. Then simply set aside your fear and whack the pintle out with a punch (carefully, I was too lazy to walk 20 steps for my brass drift) You can see it's a disaster inside. This one wasn't leaking, neither closed nor open but obviously the top o-ring exposed to the fuel is destroyed. There's some sort of grease between the two, and I'll do some homework (including re-reading Phil's thread) on what grease to use upon reassembly. Tomorrow come the 2x10x14 viton o-rings and the reassembly. 

 

 

 

 

[docc]

Topic title change to show V11 relevance . . .

Thanks for sharing your solutions, @Pressureangle and @Lucky Phil

[gstallons]

Before death , this is one activity we are all doomed to do . study this and get out there and start your practice of tightening and loosening this shutoff before it gets any worse.

[Pressureangle]

I contacted Pingel once about making something with a 16mm thread, but they weren't interested. On my list of things-that-could-happen is an adapter from 16mm to 22mm or 16mm to 3/8npt so a Pingel fuel valve could be fitted. 

[LaGrasta]

I removed mine to clean it, but I was not brave enough to whack off the knob, as you suggest.  

Hopefully, we can find an alternative or an adapter as you suggest. I'm surprised Pingel said no. 

[Pressureangle]

The o-rings came today, so I reassembled. I used a little Ospho to get rid of the worst of the white deposits- they're pretty tough. 
The o-ring grooves in the pintle are 2mm x 11mm, and the opening in the body 14+mm. The o-rings are 2mm x 10mm ID. 11mm + 4mm = 15mm, so 1mm-ish of compression on the installed rings. The only o-rings I could source quickly are 90 durometer; I used a silicone grease to install them, which is fairly sticky. Assembly was straightforward between squeezing in the vise and rotating the pintle gently. Between the hard rings (70 durometer is catalogued but not available quickly) and the sticky grease, the pintle doesn't slide extremely easily; a drop of light oil in the top of the pintle did loosen it a little bit. It will probably loosen a little with fuel exposure, and seems like a tight but manageable turn by hand for someone with thumbs that work. To do over I'd probably use a silicone spray and the softer o-rings. I can say with certainty it's tight enough not to leak. Since I don't have the means here to manage the slot/screw internal stop, I simply used a small punch to ding the top of the thumbwheel a little, which gives a plenty firm stop when it gets to the first thread, as did the compressed stock ring. I'll update further when it's in the fuel. 

[LaGrasta]

Any of these? 16mm fuel petcock

https://www.google.com/search?q=16mm+fuel+petcock&rlz=1C1RXQR_enUS1058US1058&oq=16mm+fuel+petcock&aqs=chrome..69i57j0i22i30j0i15i22i30j0i390i650l3.5552j0j4&sourceid=chrome&ie=UTF-8&bshm=nce/1#oshopproduct=pid:5324591134509243524,oid:5324591134509243524,iid:1860027824542414660,pvt:hg,pvo:3&oshop=apv&pvs=0

 

[Pressureangle]

29 minutes ago, LaGrasta said:

Any of these? 16mm fuel petcock

 

 

There are a thousand petcocks that screw onto the tank just fine, but none have the 12mm outlet for the large hose to the fuel pump, and very few have a certainty of delivering enough fuel. Not only must it feed the engine as with carbs, but it must keep the pump well fed including what bypasses the regulator back into the tank. Pingel is the only maker I'm familiar with to rest assured the flow is adequate. 

[Pressureangle]

Just a 6 month update note; 

My petcock is perfectly operational, but still harder to turn than I would like. If I had my 30 year old thumbs back it wouldn't be an issue. But it doesn't leak, and I can close it.

[Lucky Phil]

On 6/13/2023 at 9:17 AM, Pressureangle said:

There are a thousand petcocks that screw onto the tank just fine, but none have the 12mm outlet for the large hose to the fuel pump, and very few have a certainty of delivering enough fuel. Not only must it feed the engine as with carbs, but it must keep the pump well fed including what bypasses the regulator back into the tank. Pingel is the only maker I'm familiar with to rest assured the flow is adequate. 

None of this concern is really an issue. If you disassemble the original electric tap you will find a 12mm outlet hose size fed by 6mm internal passages in the tap itself. The 12mm outlet dia of the tap is only there to match the inlet dia for the external pump they chose so the hose is the same size both ends and doesn't need to be a "special"  with different end dia's. The original external pump is way oversize for the application anyway as later in tank pumps demonstrate. As we all know the theory demands in any pump application the inlet be of greater flow than the outlet but nobody told Guzzi this so the original electric tap set up is for all practical purposes a 6mm inlet with a 12mm delivery. It works just fine that way. Once again the practice and the theory don't align and in those circumstances I'm happy to go with the proven practice. Using a std size tap outlet would be fine with regards to fuel feed but you then need a hose reducer between the pump inlet and tap outlet which is an easy thing to machine up BUT the length of the hose between the tap outlet and the pump inlet is so short you can't afford to have any section at all of that hose with a length of even a little rigidity due to an inline reducer/step up fitting. Having an additional length of smaller diameter hose looped to accommodate a step up isn't practical in that area either. Not enough real estate. 

 

Phil