Weber Float Bowl Plug. Why Is It Drilled?

[69 Soft Targa]

Is there a purpose for the center and cross drilling of the float bowl drain plug?

Isn't it just a plug?

[911pcars]

Are you referring to the drilled holes through the head of the plug? If so, yes, it is merely a plug .... but it can loosen and fall out. A small quantity of fuel will follow, usually (but not always) followed by a small fire caused by a spark plug cable igniting the fuel. If not that, the exhaust manifold will as the raw fuel finds its way down looking for something hot to ignite it. The fire, if left unintended, will overheat and burn the engine insulation, melt anything plastic nearby and perhaps cause the car to burn down. This is not a pleasant thought.

Install some safety wire so this doesn't happen. Copper wire will do in a pinch. There are other screw heads on the carbs to safety wire as well.

Sherwood Lee
http://members.rennlist.org/911pcars

[69 Soft Targa]

Strangely the drain plugs do not have holes through the head...

I'm referring to a hole through the end of the drain plug which leaves the shank hollow.

The other hole is through the shank just above the threads.

Thanks for the reply. The wire locks are on all the other drilled heads.

[69 Soft Targa]

Anybody?

[911pcars]

Bob,
Sorry about the misinfo. The drain plug, as you describe, is not drilled. In fact the only bolt/screw heads drilled for safety wire are the venturi lock screws and the float bowl fulcrum (pivot) screws.

I didn't want to take the drain plugs out to verify the drilled shank so I can't answer why they're that way. I'm pretty sure they just go through the float bowl wall (no internally-drilled passages in this area), but someone else might have the answer.

Sherwood

[J P Stein]

They are drilled so's they will break if over tightened (or corroded in place ?).....sounds absurd when typed out, don't it?

They usually break when one trys to remove them....that relieves the pressure, then you use a screw driver in the new slot (thoughtfully provided by the transverse half hole that remains) to back them out.... BTDT. It does, however, beat rounding off the head of the bolt, then having to drill them out, possibily ruining the carb body. There's some Austro/Italian logic at work here, me thinks. I assume the center drill would make a good guide for a drill bit if the slot thingy didn't work....WAG on this.

This what I was told by the guy at PMO who was nice enuff to sell me 3 or 4 ( I needed 1)and ship them to me....big sale. *Soon* after that, they quit taking phone calls......oops

[69 Soft Targa]

Give the man from across the mighty Columbia a cigar!

Makes perfect sense from my experience. Found the following on a set of 40IDS I rebuilt.

1 drain plug had been replaced with a cut down bolt.

1 plug broke as I removed it. As stated a screwdriver easily removed it!
At the time I used another cut down bolt as a plug.

Always wondered... what's the purpose?... guess I didn't make the connection!

So, about those spare plugs you received from PMO...

Thanks!

[J P Stein]

I have one left. My Weber bits get picked over infrequently, but steadily. I haven't bought any for 2-3 years. If you're really hurtin' we can work something out. Maybe we can do a group buy

[69 Soft Targa]

Originally posted by J P Stein
I have one left. My Weber bits get picked over infrequently, but steadily. If you're really hurtin' we can work something out. Maybe we can do a group buy

Hang on to it... you never know.
I ain't hurtin' that bad.




BTW. The broken plug has been made into a float level gauge.

A little epoxy. Drill through the head. Attach measuring device as seen on another thread.
Keep the info coming guys!

[joehahn]

i remember over tightening one of those screws and it breaking....i totally freaked til some kind sole on the board told me about that nice slot the drilled hole makes for removal. It did suck having an inoperable car whilst waiting for 1 tiny screw to fly across the country to me.

joe 68 L

[DavidPorter]

Hey, anyone have a transition hole access plug for sale? I think that's what it's called. Brass slotted-head solid threaded plug. If you take it off you see the two holes drilled in the bottom of the hole. I lost one.

[studeb]

Not to be anal, but there should be three holes visible through the inspection port. The caps can be bought from Pierce manifolds part number 61015.009. Probably a couple of bucks. The drain plugs are part number 61002.006.

[206aa]

PMO should have them as well. I snapped a float bowl plug rebuilding my carbs a couple of weeks ago. I went ahead and replaced all of the hardware that the PO or his mechanic had mangled the heads on. .


--Alan

_________________________
1968 Porsche 911 2.4t

[J P Stein]

I did go buy some metric bolts....just your standard cad plated steel that did the trick when *I* was hurtin'....still have them somewhere. I don't remember the size, but they are a standard metric fine thread and not some oddball special zoot
sumb!tch.

[studeb]

The thread size is metric 7mm x 1

[avendlerdp]

The holes are there so you can drain the bowl w/o fully removing the plug. This is a great thing if you ever get water in the gas or if there is a ton of rust in your tank you can loosen the plug and drain the bowls!!!!

Oh, and all those other reasons as well.

Alex

[J P Stein]

Originally posted by avendlerdp
The holes are there so you can drain the bowl w/o fully removing the plug. This is a great thing if you ever get water in the gas or if there is a ton of rust in your tank you can loosen the plug and drain the bowls!!!!

Oh, and all those other reasons as well.

Alex

Hay, I like that better. One can slowly dribble gas all over the place rather than do it quickly. ...and if the head of the bolt breaks off, the bowl still drains...which is what you were trying to do in the first place, eh?. Makes sense to me.

[DavidPorter]

OK, I can polish brass if I want, but what does everyone do about the steel parts? The idle screws, air screws, springs, etc? Cad plating would be nice if you could find it. Anyone use the Eastwood home plating system?