Flat spot on acceleration with webber 44s

[aliviles]

I have a '74 914 with what I believe is a stock 1800cc engine. The car is fitted with a pair of new Webber 44s which I bought in the USA and were originally jetted for US petrol.
The car is back in the UK now and I have been using it regularly for a couple of years. It runs OK but has a flat spot on hard acceleration between about 2900 and 3400 RPM which I can't seem to get rid of. I have taken it to my local rolling road and they made it a bit better but haven't resolved it.
Does anyone have any experience of this or any recommendations on how to resolve this flat spot?
Many thanks,
Ali

[chief]

I appreciate that it has run okay, but I would have thought 44's were a bit big for an 1800. Have they been choked down do you know?

[aliviles]

No, they haven't been choked down as far as I am aware.
I agree that they are probably larger than required for the car, but they are what was recommended by CB performance for the car when I bought them. Perhaps they are good with the lower octane fuel in the US.

[Nige]

Guess it's running an 009 dizzy as well?

[aliviles]

I think so, although I am away from the car at the moment so can't check and I can't honestly remember.

[chief]

My thoughts would be those big carbs. Your mixture speed would be quite slow which could cause that nasty flat spot. Difficult one to definately put your finger on without seeing it. Mixture speed with fuel drop out would sit on the walls of the inlet/ heads and produce sypmtoms you describe.

[aliviles]

Many thanks for your comments on this, that makes sense, although it is unfortunate if the 44s are not really the right thing for the car.
I guess I may need to try to sell those 44s and get some 40s instead.
Thank you for your help

[Mike Smith]

Ali,
Look down the carbs at the reduction pieces (the Chokes) is the a size on them 38. 36, 34 ???

Mike

[chief]

Back in the day you could choke them down a few MM. Not sure what is available nowadays.
My advise would be give Angus a call at Greatworth Classics and chat through the problem. He will know what's available. Also a top, honest chap, so will give you straight advise with options.

[Mike Smith]

My guess is 34 is where you want to be and then go back to the rolling road