Solex Expert Level Question
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Solex Expert Level Question
Hello all, I am getting into the real fine tuning here and have a problem with fuel injector nozzle quantities. Carbs are Solex 40P11 freshly rebuilt. New accelerator pump diaphragms, new injector nozzles #40, new pump jets #50. The accelerator pump rods are disconnected so this isn't just an adjustment issue. I am using the Porsche measuring vial and have measured many times. Three of the injectors measure .65 and one measures .75. (Porsche recommends .45 to .65). Do any of the experts have any idea what would cause this imbalance? Is there a solution to get them balanced? Maybe use different size pump jets and/or injector nozzles? Am I looking for too much precision here? Should I just ignore the variance between .65 and .75?
- Martin Benade
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Re: Solex Expert Level Question
How are you getting a repeatable volume? The length of the pump rod is the adjustment to set volume.
Have you tried swapping the jets to see if the different volumes move with them?
Have you tried swapping the jets to see if the different volumes move with them?
Cleveland Ohio
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04 Sienna
- Phil Planck
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Re: Solex Expert Level Question
Could be crud in nozzles. Take apart and clean. Dont lose check balls.
Split or solid shaft?
Split or solid shaft?
Phil Planck
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Re: Solex Expert Level Question
These are solid shaft. The nozzles are all brand new so there is no crud in thetr
- John Brooks
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Re: Solex Expert Level Question
If you have a set of jet reamers, you can measure the hole in the end of the nozzle. I slide a reamer in the hole and slowly turn it counter clockwise until it’s seated. Then I put my thumb hail on the reamer to mark the nozzle face. Then I measure the spot with a micrometer or a dial thickness gauge. The higher flow nozzle must have a larger hole where it’s crimped on the end.
You can ream all the nozzles to the same size, then adjust the output with the linkage stroke.
Stahlwille 11085 Jet reamers, P/N. ST74310001
You can ream all the nozzles to the same size, then adjust the output with the linkage stroke.
Stahlwille 11085 Jet reamers, P/N. ST74310001
John Brooks
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62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965
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Re: Solex Expert Level Question
Hello Martin, the pump rods are disconnected and I am manually moving the pump levers for 2 full strokes.
I have tried swapping the pump jets but the quantity doesn’t change. It is always too much for cylinder #4
I have tried swapping the pump jets but the quantity doesn’t change. It is always too much for cylinder #4
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Re: Solex Expert Level Question
John,
All of the nozzles are brand new # 40. I have moved them around to different cylinders but I still get the same measured quantities. Cylinder # 4 is always too much.
All of the nozzles are brand new # 40. I have moved them around to different cylinders but I still get the same measured quantities. Cylinder # 4 is always too much.
- Mike Wilson
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Re: Solex Expert Level Question
New nozzles...I'd make sure they are the same size as John suggested.
Mike
Mike
Mike Wilson
Lomita, CA
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Lomita, CA
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- David Jones
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Re: Solex Expert Level Question
Below the accel pump jets mounts on split shaft Solex carbs there are brass cylinders that limit accel pump output. Are they present in all the circuits.
If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
David Jones #9715
Cymru am byth
David Jones #9715
- Phil Planck
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Re: Solex Expert Level Question
Rich
Why not try adjusting output per the manual? Maybe when you get down to .35 cc per 2 strokes that difference will disappear.
Why not try adjusting output per the manual? Maybe when you get down to .35 cc per 2 strokes that difference will disappear.
Phil Planck
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Re: Solex Expert Level Question
1) different pump jets (one by side).
2) different nozzle sizes (input and output holes)
3) different brass balls weight
4) as mentionned previously, dirt/dust somewhere.
But the difference is not huge.
2) different nozzle sizes (input and output holes)
3) different brass balls weight
4) as mentionned previously, dirt/dust somewhere.
But the difference is not huge.
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Re: Solex Expert Level Question
Its more likely to be the nozzles. Try swapping the nozzles between carburetors, left to left (cyl 4 to cyl 2). Make sure you can hear the check valve ball bearing rattling in each nozzle, sometimes they get stuck in one place. Check the fiber gasket below each nozzle, maybe there is a piece of fiber blocking the passage. You will probably need a new pair of gaskets.Rich Goold wrote: ↑Thu Mar 16, 2023 1:06 pm Hello Martin, the pump rods are disconnected and I am manually moving the pump levers for 2 full strokes.
I have tried swapping the pump jets but the quantity doesn’t change. It is always too much for cylinder #4
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Re: Solex Expert Level Question
The nozzles are all new but I rotated them anyway, no change. Cylinder #4 still getting too much fuel. Nozzle gaskets are new as well.
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Re: Solex Expert Level Question
David, the brass cylinders to limit output for each circuit might be my problem but I don’t recall seeing anything like that when I rebuilt the carbs. My carbs are solid shaft, should they have the brass cylinders as well?
- David Jones
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Re: Solex Expert Level Question
Not in solid shaft carbs.
If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
David Jones #9715
Cymru am byth
David Jones #9715