Fuel Primer/Tap Body

[Bensdexta]

I'm rebuilding my fuel tap using a chain saw priming bulb, after Stefan.

But has my fuel tap a manufacturing fault....?

Overall view of my 2nd hand fuel tap which, once upon a time, did work.


View looking down fuel inlet. Note the partially drilled hole which doesn't open cleanly into the gallery below. There is just a small perforation for the fuel to flow through.

View looking into the gallery into which the shut-off tap screws. The perforation is just visible. Also the bottom of the inlet hole from above has deformed into the gallery.

Is the body supposed to look like this?

Or should I gently open out the perforation to make a cleaner hole into the gallery?

[Bensdexta]

Does anyone know how to reassemble this?


I took it apart but can't see how it goes together - how dim is that?

Clearly the clip goes in the slot, but how? The only way I can get it in, it keeps falling out....

Anyone mastered it??

[Mervyn Spencer]

Hi Ben

From my experience, turn the black plastic part into the tap fully, and then squeeze the spring closed with a pair of long nose pliers - feed/thread it into the both slots ie. Top and bottom. that should hold the plastic part in and only allow it to move out sufficiently to allow diesel to flow. Not easy to get it through the bottom hole but persevere it will eventually come through. Thats how I did mine some time ago.

Good luck

[Mervyn Spencer]

Hi Ben, did you manage to get the fuel tap reassembled?

[Bensdexta]

did you manage to get the fuel tap reassembled?

No, still haven't done it! I can't even get it in without the tap, never mind with the tap screwed in.
Perhaps I'm not being brutal enough!
Right now the body of my primer is being drilled to put in the nipples a la Stefan. I think Stefan had the same problem with the spring clip and in the end made his own clip. Perhaps I'll have one last try before I too make a Stefan clip!

Most of the bits for my Stefan primer below:

2nd hand body
machined cup & cover, generously supplied by Stefan - what a champ
2 fuel nipples (Stihl 0000 988 5211)
Rubber fuel pipe (Stihl 0000 930 2802)
Chain saw primer bulb (Stihl 4130 350 6200)
Ensat bushing (choice of 3!), M6 internal thread. Self-taps into a 9.5mm plain hole.

I hope the winter's treating you kindly down there. It's been pretty hot here for the past few days - soon be a drought!
All the best,

[pjjms]

Sounds like more force required. The 2 points facing in need to protrude right into the body so it will be tight.

[Mervyn Spencer]

Ben I don't recall really battling with my spring, maybe my spring was a bit weaker. As PJJMS says maybe a little more encouragement.

Thanks for asking, the mornings and evenings are fresh but nothing under 10 degrees Celsius, still going to work in a short sleeve shirt. We had a 31 degree day today and expecting a cold front tomorrow though.

[Chug-A-Lug]

Or should I gently open out the perforation to make a cleaner hole into the gallery?

I remembered this topic from a while ago. I've just recieved a brand new primer/tap in my efforts to restore some originality to the fuel system. My tap also only has a tiny perforation. I almost got the drill out earlier and thought I'd ask, did we ever answer the question? Should the hole be opened or left as a tiny perforation...?

[Bensdexta]

Or should I gently open out the perforation to make a cleaner hole into the gallery?

I remembered this topic from a while ago. I've just recieved a brand new primer/tap in my efforts to restore some originality to the fuel system. My tap also only has a tiny perforation. I almost got the drill out earlier and thought I'd ask, did we ever answer the question? Should the hole be opened or left as a tiny perforation...?

I consulted Stefan by email, who kindly studied my photos and advised that he thought it was indeed a poor bit of machining which can usefully be tidied up. So I took a very small round file and gently filed the perforation to make a cleaner hole. I think you could also use a drill if you are very careful.
All the best,

[Chug-A-Lug]

Thanks for the reply.

I've not yet attacked the tap with my drill. I went to test fit everything together this evening and found that neither fuel line would fit the tap. It seems that both threads in the tap body are marginally too small. I really don't want to be sending this back.

Do you think the tap body could be machined for metric fittings? While the fuel lines themselves have imperial fittings?

If this is the case I'll just get a couple of metric fittings and re-do the ends of the fuel lines.

What a pain in the neck!

[YorkshireDextaMan]

Thanks for the reply.

I've not yet attacked the tap with my drill. I went to test fit everything together this evening and found that neither fuel line would fit the tap. It seems that both threads in the tap body are marginally too small. I really don't want to be sending this back.

Do you think the tap body could be machined for metric fittings? While the fuel lines themselves have imperial fittings?

If this is the case I'll just get a couple of metric fittings and re-do the ends of the fuel lines.

What a pain in the neck!

I would'nt doubt for a miniute what your saying fella, but that sure looks like a Dexta tap and unless the threads are damaged (which can happen) the pipes should screw in, However i can tell you they can be a right begger to get started, Question ,have you tried to start them with the tap of the tank, just to make sure they fit.? Ok, You could try this , leave the tank loose till you get the threads started, Jim.

Sorry, , i just realised , you have a new tap.
BTW how did you get on with cleaning the tank.?

[Bensdexta]

Do you think the tap body could be machined for metric fittings? While the fuel lines themselves have imperial fittings?

The threads on my original tap/primer are 1/2" UNF (20 turns/inch).

[Chug-A-Lug]

Well I suppose I'll visit a couple of local motor factors with the tap in hand and see what they say. If I can get fittings to fit it'll save the hassle of returning it.

Will I have any problems if I want to change the nut on the end of a steel fuel line? Does a steel fuel line still use a brass olive? It's also brand new from Agriline, but fits fine onto lift pump, just seems to be the tap body giving trouble.

[Bensdexta]

It's also brand new from Agriline, but fits fine onto lift pump, just seems to be the tap body giving trouble.

So the Agriline pipe doesn't fit the Agriline tap? If so,
Suggest you ask them what is going on

[Chug-A-Lug]

Correct.

The agriline pipe fits at the fuel lift pump, but won't fit at the tap. The old (maybe original) pipe to the manifold, also doesn't fit at the tap.

I suppose it would be best the call them.

This is ridiculous!

[Chug-A-Lug]

Ok,

so I called Agriline and my suspicions were correct. The tap body has been machined for a metric thread (they admitted that approximately half thier stock has this fault, but hadn't realised untill after they sent mine). They suggested that others who have called them with this problem are re-tapping the tap body for the UNF fittings.

I'll be buying myself a couple of UNF taps at the weekend as I really don't want the hassle of sending this thing back. Plus I get to keep new tools and reuse at a later date if necessary, and probably cost less than the postage!

[Bensdexta]

I'll be buying myself a couple of UNF taps at the weekend as I really don't want the hassle of sending this thing back. Plus I get to keep new tools and reuse at a later date if necessary, and probably cost less than the postage!

Why not ask them to send you a UNF one FOC? The metric one you have is clearly faulty, unsaleable & I can't see why they would want it back (they let me keep my faulty exhaust manifold)

[Bensdexta]

I've almost finished rebuilding my fuel tap using a Stihl chain saw priming bulb, after Stefan.
This is how it started - as a u/s 2nd hand fuel tap.

Question:
How do I fix my new tubular fuel filter into the top of the primer body? Some sort of diesel proof glue?
IIRC it originally had some sort of string caulking holding in the filter (see below).

OK discovered that my new plastic filter just pushes into the top of the fuel tap - simples

[Bensdexta]

Some photos of my Stefan Primer, see earlier photo of parts^:

Drilling out the primer body for centre bolt and interference-fit Stihl nipples


Self-tapping Ensat bushing with M6 inner thread


Body with bushing and nipples fitted


Trial fit of M6 bolt


Trial fit of cup to body


Cover milled to fit primer bulb


Trial fit of bulb to cover


Cover being welded to cup



Trial fit of bulb


Finished primer complete with internal rubber tubes (Stihl) from nipples to bulb. Two side holes are to release the bulb should that be necessary