Gas dripping - 3&6, 914-6, 1970, all stock Options

[ctc911ctc]

Teeners! and SuperHawk!

Been awhile - i trust all is well in TeenLand

I just purchased a large property 2 hrs north of Boston - have a
car barn' where I believe I can store 12+ 914s!

I was prepping my 914-6 for the drive - recently have had carb problems that I could not get sorted so I bought a pair from a Teener in FL. Nice shape, I checked all of the calibrations, etc. All seemed correct

I drove from Cambridge to Lexington, shake down drive, got it up to 75mph ran great.

Brought it back to my driveway and smelled gas.......huh? .....where's that fire extinguisher??

No leaking underneath (yes I replaced the plastic lines with steel when I rebuilt the car.)

Took off the aircleaner manifold and gas was pooling in the #6 and #3 carbs. Seemed to be siphoning. My drive way is on a 6degree slant and the car was facing uphill, so 3 and 6 are in the back......

After they stopped, there was no gas in any of the bowls...... I could not get the accel pumps to spray.

I restarted the car after a few minutes and could not recreate this draining.

SuperHawk, you usually can call it first time - what is going on and should I be concerned?

CTC911CTC

[Superhawk996]

Thanks for the vote of confidence but I think you nailed it.

A 6 degree slope is not going to help. As you probably know from siphoning gas from a gas tank with a hose, once the siphon gets started it will self sustain. In this case until the float bowls drained.

I wouldn’t panic but I’d monitor and try to park it on a flatter area especially when hot. Don’t want this occurring on a regular basis washing down cylinder walls and diluting oil. An occasional occurrence isn’t a big deal but I wouldn’t want it occurring every time. Do you know if you’re running carb insulators? That may help if you’re not already running them.

Glad you finally got your carb tuning issues sorted and are driving. (IMG:style_emoticons/default/driving.gif)

[mskala]

Do you know if the carbs you bought have the 'anti-percolation' modification, which
I think was created just for this scenario?

[930cabman]

Congrats on the new place, and 12+ 914's!! must be crazy

First I would monitor the issue and see if this is happening all the time? Possible the float levels are high in those bowls

[porschetub]

Congrats on the new place, and 12+ 914's!! must be crazy

First I would monitor the issue and see if this is happening all the time? Possible the float levels are high in those bowls

(IMG:style_emoticons/default/agree.gif) ,float levels are a good start ,used carbs are used carbs after all !!!.
My experience was newly rebuilt carbs and wet throats on most cylinders @ idle ,turned out the fibre washers supplied in the kit for needle and seats were the wrong thickness, used the old ones and levels were spot on ,the rest is history .
My final setting were done with a PMO float gauge and it's a great tool for those of us with Webers or Zeniths .
Cheers.

[ctc911ctc]

Do you know if the carbs you bought have the 'anti-percolation' modification, which
I think was created just for this scenario?

huh?

Never heard of it - is there a link?

Will ask my AI,

CTC

[ctc911ctc]

Congrats on the new place, and 12+ 914's!! must be crazy

First I would monitor the issue and see if this is happening all the time? Possible the float levels are high in those bowls

(IMG:style_emoticons/default/agree.gif) ,float levels are a good start ,used carbs are used carbs after all !!!.
My experience was newly rebuilt carbs and wet throats on most cylinders @ idle ,turned out the fibre washers supplied in the kit for needle and seats were the wrong thickness, used the old ones and levels were spot on ,the rest is history .
My final setting were done with a PMO float gauge and it's a great tool for those of us with Webers or Zeniths .
Cheers.

Set the floats and measured the levels with the screw on sightglass from Porsche,

seems ok....

[mskala]

Look at This Pelican post (#10 in the thread)
for pictures of the holes and the PMO tool.

[ctc911ctc]

Yow

Master Class thread

They address 2 issues

1) decouple thermal coupling to engine (boiling sound in carbs)
2) vacuum relief hole drill into the top of each bowl

Neither are interesting to me, too much R&D and guessing

Wow!

Look at This Pelican post (#10 in the thread)
for pictures of the holes and the PMO tool.