weber mixture screw profile change

[jordanpryce]

I ordered new screws from Partsklassik and they differ from the old ones. Carbs are IDTP40's. Is this a running change? I'm replacing all six screws, I just want to know that they will work correctly.

[Paul W]

Believe the new screws are for IDA carbs. I have these in the carbs of my 69T and work fine. Much easier to tune due to the taper.

Cheers

[trdking]

What ever you do, don't get rid of the old screws. They will probably be a collector someday for an original resto

[chris_seven]

Left Hand is typically IDA, IDS and IDAP Right Hand is IDTP

There is a third version found in very early IDA carbs which also used a flat washer to back up the O ring.

[1QuickS]

My take on this is the stepped tip prevented twisting the tip off if the IDA type was closed too tightly. However, the sensitivity to mixture adjustment is crap with the IDTP version. IDTP and the other Webers all used a 1.0mm dia hole for the mixture screw so substitution with the earlier type is fine.

Beware: Some replacement mixture screws are made of brass and will be easy to twist the tip off if closed too tightly and they will groove the tip also. The screw you have is not per the OEM design which had an un-threaded body portion like the IDTP version, I assume it is from a similar Weber carb that will fit ours. A non-issue comment, just being complete.

[jordanpryce]

Thanks Paul. Gentle as she goes.