Solex 1BBL with manual choke, adjustments

[trumanwoll]

This might have posted. Am trying to locate idle adjustment screws or find a vacuum leak. Can't keep idle, loads up and runs rich, stalls repeatedly. Adjusted throttle linkage, better but idle now high and still rich, can't keep it running. How does one track down vacuum leaks?

[jimk]

Check your idle jet for dirt. It doesn't take much of a small speck to plug it. May need a magnifiying glass to see it. That carb is notorious for dirt in the jet.

[Guest Anonymous]

someone will post a pic, but the idle speed adjustment is a screw where the linkage joins the carb. The idle mixture screw is on the passenger side - it gets tiny pieces of crud stuck in the tip.

To check for a vacuum leak, spray carb cleaner at different spots or wave an unlit propane torch around suspected places. When the idle improves u have found your leak.

[trumanwoll]

I have sort of stumbled my way into a better idle. I have now been able to back off the linkage adjustment and have a solid, slightly high, and steady idle. Here is what I found: The hose that takes in the fuel was in need of a few small turns. Now my issue it that the pump area with the diaphram on the radiator side of the carb is leaking out the bottom. One can see it without the engine running if you manually throttle it and look under from the pass side. Do you know if that can be fixed in a carb overhaul or is this a dead horse? Runs great but raw gas is danger.

Hate to give up on keeping the old guy authentic.

Thanks for the info.

[Guest Anonymous]

If you can get the diaphragm it is easy to replace - 4 screws.

[trumanwoll]

Have to be dozens of them around. Is that the most likely leakage point? Thanks for the help! And hope. Without better access/tools those four are damn tight and rusted in.

[trumanwoll]

I am not sure, actually positve that I have not located the idle jet. There is an idle adjustment crew on the passenger base of the carb. Am still horsing with the air intake on and stumbled to a better steady idle. Spotted a leaking diaphram on what I think is the accellorator pump, raw gas not good, but tightened the return gas line and big improvement. Now need to locate the diaphram.

Thanks

[Timmer]

The idle jet for the Solex 36-40PDSI is just above the accelerator pump diaphragm, left side, it will unscrew., clean that jet by either soaking in carburettor cleaner or using compressed air; don't put any device into the oriface of the jet to clean as you don't want to damage it

Tim

[c.d.iesel]

or

[Timmer]

One more photo; just above the accelerator pump, to the left, that's the idle jet; image is fuzzy so click on the image and it will enlarge.

Tim

[trumanwoll]

I have the 1 BBL which is not the same as your picture. I thought it was a 32 DDITA or something like that. Got things much better, located the 2 screws, left the long spring loaded screw alone, and backed down the idle with the adjusting screw on the linkage. It is spot on perfect and the leak is none existant.

Thanks!

[Timmer]

Ok, gotcha,

The 32 DIDTA is familiar as well; I had the 36-40PDSI Solex on a 4 door 1969 BMW 2000. Sounds like you have things in check

Tim

[Mike Self]

doesn't seem to help, check your vacuum advance unit (on the dizzy) to make sure the diaphragm isn't punctured. Do this by removing the vacuum line at the carb end and sucking on it. You should feel resistance, and if you remove the dizzy cap, you should see the point plate move. No resistance or movement, and you need a new vacuum advance unit.

In addition, check for other vacuum leaks (uncovered vacuum ports, warped carb base, loose intake manifold etc).

cheers

mike

[Timmer]

Good recommendation Mike and pick up a solex rebuild kit, many places still have them; La Jolla Independent, Autohauz, Pelican Parts to name a few, I bought one from Carl, at La Jolla Independent for the 1969 2000 I had.

Tim

[TobyB]

If it's a 32, are you sure it's not a Weber? There was a small 1bbl agricultural

Weber that was specified as a 'direct replacement' for a long time-- I think it's

even still in production. Parts for it are easy to find.

It worked well on my dad's 68 Allis Chalmers combine...

t