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TOC · New user Joined: 17 Jan 2009 Posts: 3

Been fighting a big flat spot in my 2.4L Jag with twin Solexes.

Cleaned, lapped, rebuilt, stutters, pops, yet idle good and WOT good.

Played with air bleeds, float levels, all to no avail.

The book calls out Solex #110 main jets.
These are what are installed.

I had the "old" carbs (Mercedes?) and I swapped out the mains (one #130, the other #137.5) and the flat spot is GONE.

I am trying to locate some new mains, but what has changed?
My experience is mains don't really change, even with a light engine rebore.

Why do factory mains no longer function?

Thanks.

TOC · New user Joined: 17 Jan 2009 Posts: 3

I guess nobody responds on these forums.

It car was extremely cold-blooded, popped and all sorts of stuff until at least
70C.

I found a VW outfit that would sell me some 120's and 130's.

120's are better, 130's about solve the issue
But why?

I am quite good on Flathead Ford 2bbls, and changing mains has never, ever
changed idle speed nor idle mixture.
Yet, swapping out mains only causes major changes to idle speed and idle
mixture.

The symptom is still a slight "nibble" or surge at dead cruise, no power applied or removed.
Tip into it lightly, problem is gone.

No manifold leaks, dwell dead on, timing adjusted (as per manual) to light ping lugged in 4th on a hill.

What am I missing on this?

Thanks.