Off-idle hesitation . . .

[tekenaar]

For a moment there, I thought I might have to eat my words (as in, crow) regarding Solex usage on a purely stock engine.

Until about two weeks ago, everything was hunky-dory with my low-mileage, completely-stock '69 Kadett LS . . . including the much-maligned '69 Solex carburetor! Then, after idling for a bit at stop lights, the car would hesitate momentarily when accelerating from a dead stop. The engine also died a couple of times pulling out into traffic from a parking lot . . . not good!

As luck would have it, the weather turned nasty down here, high winds, lotsa rain and temps in the mid 20s at night . . . HEY, that's COLD for Texas! Well, I no longer futz with cars when the weather doesn't cooperate, so the problem remained. The weather finally broke somewhat yesterday, enough so I could look into the problem. Not quite ready to throw in the towel just yet!

Let's see now, hesitation off-idle . . . usually it's something not right with the carb's accelerator pump. Removed the air cleaner to better observe the pump nozzle spray in the carb's primary. Bit of a drip and drizzle, not the expected steady stream from the nozzle when the primary throttle is opened. Hmmm . . .

This is an older Solex, which has a sprung actuating rod connected to the pump arm, not roller and cam actuation like the newer Solex pumps use. Got a plastic oleo tub and removed the accelerator pump cover, draining fuel into the tub. NOTE: since the pump chamber is gravity fed from the carb's fuel bowl, it will drain ALL of the fuel out of the bowl when opened!

Next, I carefully removed the pump diaphragm and tension spring and let the pump cover just hang from its actuating rod. Noticed a bit of dirt from dried fuel in the bottom of the accelerator pump chamber, due to the carb sitting dry for several years while replaced with a Weber 32/36 by PO. Cleaned the pump chamber and found a small cylindrical brass plug. Hmmm . . .

The pump chamber has three holes in it, so where does this plug go? Let's see, the pump must have a fuel entry (gravity fed) and exit (pressure) hole to function properly, so which of the three is normally plugged? Logically entry hole should be level with bottom of fuel bowl or close to it. One down.

Exit hole can be anywhere in chamber since it's fed under diaphragm pressure, but must feed a connecting passage to the nozzle in the primary. Two down . . . plug goes into the remaining hole. See, it's all in the little details . . . problem solved!

Never did like crow all that much anyway.

[GTJIM]

So Soleii even "solex" parts of themselves!

Nice save BTW .......