Warped Webers

[carsngolf]

I have never been happy with the light throttle acceleration of either of my cars. I have spent hours and hours cleaning, adjusting, changing jets, etc. with little success and finally concluded either Weber carbs aren't designed for low rpm work or I was simply incompetent with emphasis on the latter.

Then last week, I had a pair off for setting float levels and in the process, noted some leakage around the accelerator pump housings. I took them apart and even with the naked eye it was apparent the mating surfaces were warped! The only way I could see to fix it was to mill down the high spots . Fortunately, I have a milling machine and after creating a mounting fixture I began cutting. It took .030" to .045" to get flat surfaces on the cap and .020" to .030" for the housing! That's around 1/16" of an inch for non machinist types. I realize I've lost some of the volume from the chamber but what a difference in performance! Both cars now react smoothly and quickly with no hesitation or spitting. Apparently, there was very little flow through the pump nozzles on light throttle as pressure was lost from the leaky housings.

[Mo_Gearhead]

Had the exact same problem with my 38 yr old Webers. Rebuilt them but pumps leaked. Took them apart and (just like Turbo valve covers) put them on a plate of glass with 600 grit paper attached, found them to be warped. Took almost two hours (!) on each one but leveled them by hand. Started with 600 grit, then 1000, then 1500. Perfect, no leaks!

[unimog406]

you guys might be onto something... I've had a very similar [if not the same] problem plaguing my webers for some time now....
thanks!

[dvkk]

Originally posted by Mo_Gearhead
.... put them on a plate of glass with 600 grit paper attached, found them to be warped. Took almost two hours (!) on each one but leveled them by hand. Started with 600 grit, then 1000, then 1500. Perfect, no leaks!

When you start with 220 grit, you are done in 10 min. Also, don't be afraid to use the hand milling machine.