Porsche 912 solex carb

[pud]

Hi all. I have a 1969 targa 912 , I ran out of petrol , re filled and turned on the electric fuel pump for e few seconds without the engine running , checked the carbs and noticed some fuel possibly coming out from the butterfly spindle , is this a problem , thanks , Andy

[WFBowen]

Andy:
I'd guess that your float needle valve failed to close and fuel ran into the throat of the carb. Might be time for a carb kit & cleaning. When carbs get fuel after running completely dry the floats sometimes stick in the open position. Once it's running again spray a little carb cleaner on those throttle shaft bushings & listen for a change in RPM. They should be airtight & are a very common source of rough running motors.
Bill

[pud]

Thanks bill, I have run the engine for a short time and the petrol on the outside of the carb does go , I have a problem with the engine running rough at the moment , I have not long had the targa , it seems to be missing causing the engine to rock from side to side , I have replaced the plugs , checked the point gap , but am waiting for new HT leads , should I replace the coil as well, thanks Andy ,

[Rick Becker]

Andy,
Solexes are notorious for wear and leakage at the butterfly spindles; the folks at 356 Carburetor Rescue just remanufactured mine, and they're awesome now. Here's their link:
Page Title

[pud]

I have now removed one of the carbs and noticed one of the fuel delivery tubes on the top is blocked and also the float has fuel in it ,

[WFBowen]

Actually great news - The float no longer does its job & the accel. pump is no longer delivering to a cylinder. Time for at least a teardown, cleaning, kit & replacement float.
Bill

[pud]

Hi bill , thanks for your advice , I have ordered a gasket and washer set , I will go through the carb and clean all the jets etc , not sure what to do about the float , I'm thinking once I get the fuel out of it maybe try and repair it ,

[Cobra06]

Originally Posted by pud

Hi bill , thanks for your advice , I have ordered a gasket and washer set , I will go through the carb and clean all the jets etc , not sure what to do about the float , I'm thinking once I get the fuel out of it maybe try and repair it ,

New floats are about $25.00, if you patch them and change the weight, could cause you problems

[pud]

Hi , cobra06 , I heated up a screwdriver and melted over the small pin size hole , hopefully will be ok , if I have trouble do you know where I can get a new float for the solex carb , I'm in the uk , ps the carbs are solex 40Pll cheers , Andy

[Cobra06]

Try Eurocarb, they're in the UK. Or ALFA1750 on eBay, he's in Italy and has pretty much all of the SOLEX 40 parts

[pud]

Thanks cobra, I have ordered a new float from euro carb , thanks for the help ,

[pud]

This is driving me nuts , I've just tested the carbs by turning on the electric pump for a while , I'm thinking petrol will fill the bowls and then the petrol will be cut off by the petrol valve , but no , petrol is filling the throats , is this just a case of the shut off not working , ?

[djdsc]

Originally Posted by pud

This is driving me nuts , I've just tested the carbs by turning on the electric pump for a while , I'm thinking petrol will fill the bowls and then the petrol will be cut off by the petrol valve , but no , petrol is filling the throats , is this just a case of the shut off not working , ?

Running too much full pressure with an electric fuel pump will easily over pressure the float valve (floats). For water ever reason you have the need to use an electric fuel pump then you must install a fuel pressure regulator and dial it down to around 2psi. There is nothing surprising with your situation.

[pud]

Hi , I have a fuel pressure regulator on and have it set at 2 psi

[djdsc]

Originally Posted by pud

Hi , I have a fuel pressure regulator on and have it set at 2 psi

Excellent!!

Search around on the 912bbs.org for information regarding the difference in the available Solex needle float valves, there is a good and a bad version AIRC.

[Peter Graham]

Originally Posted by djdsc

Search around on the 912bbs.org for information regarding the difference in the available Solex needle float valves, there is a good and a bad version AIRC.

The 'good' (stock) float valves are 1.75 and have a spring-loaded roller ball in the plunger; the 'bad' are 2.0 and have solid plunger.

Photo: 'bad' on left, stock on right.


Peter

[pud]

Hi I have just bought 2 new float valves , looks like the one on the left but has roller ball on the pin , hope they will be ok ,

[Peter Graham]

Originally Posted by pud

Hi I have just bought 2 new float valves , looks like the one on the left but has roller ball on the pin , hope they will be ok ,

The orifice size is critical too: make sure they are stamped '1.75' and not '2'.

Peter

[pud]

Thanks peter ,