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Hi,
I am using a Zenith 26VF down draught carburettor on my special. The carburettor is the smaller of the two Ford used on the Popular range and is in good overall condition. It runs well at top end revs, with nice, clean plugs etc. However it has a slight flat spot when accelerating from stationary. I am unable to clear this through normal adjustment. The jets are I believe are the standard Ford jets main,70 comp 65, slow 60. I have tried, with no success, the standard Austin 26 VA jets. I believe this carb change was a mod used on A7s many years ago, does anyone have any experience of using this carb and what jet sizes were used.
Tod
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Location: Nottinghamshire. Robin Hood County
Car type: Austin Ruby Mk1 1935
I had a similar problem to this with my Ruby and a Zenith 26VA carb. After much fiddling with the carb cleaning jets and passage ways together. With various amounts of adjusting the mixture screw to no avail. The problem was solved with a very small adjustment of the ignition timing.
John Mason.
Would you believe it "Her who must be obeyed" refers to my Ruby as the toy.
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Location: Essex
It's been a while since I ran my Rubh with one, but I am pretty sure that the jet sizes are given in the Companion...
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20-08-2021, 09:54 PM
(This post was last modified: 20-08-2021, 09:56 PM by Tod.)
John,
Thanks for your reply, like yourself, after adjusting the carb to no real improvement my next adjustment was to the ignition timing which gave a slight improvement, but still there was a slight flat spot.
My feeling is problem lies in the jet sizes,
Thanks,
Tod
Nick,
Thanks for your reply, I will check the Compaion tomorrow.
Tod
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Location: Auckland, NZ
I dont know if the Ford carb has a gasket or not but for carbs with the idle adj on the lid the lid should fit neatly to the top without significant gaps. Although usually shows as idle problems. A large compensator is usually more likely to assist than a smaller one. For a similar siamesed port 4 cyl engine, the jets relate more to the venturi size than any other factors so what works with the 8hp Ford is unlikley to be wildly wrong for others.
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Location: Essex
21-08-2021, 07:56 AM
(This post was last modified: 21-08-2021, 07:57 AM by Nick Lettington.)
75 main and 50 compensating... nothing's mentioned about the slow.
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This morning I changed the Jets as per Nick's message. I am happy to report all is well now.
Thanks to all who responded.
Tod
