Author Topic: Carbs  (Read 1743 times)

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Offline Alan

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« on: 20 Dec 2018 at 00:27 »
I have 2 off 2 3/4 hp engines both 1924 both with very similar updraft carbs. One is marked TV 688 and the other a slightly mangled VD 1596. Are both correct to use and is it possibly just jet differences ( I havenít got the equipment to measure)?
On another subject and might help ; a classic car magazine gave highly recommended reviews to a newish product called Kano Kroil for freeing up badly corroded nuts and bolts etc. thought I would give it a try and worked  for me as I tried just a drop on a couple of bolts untouched for decades and loosened up within minutes as per the review.

Offline cardan

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Re: Carbs
« Reply #1 on: 20 Dec 2018 at 20:16 »
Hi Alan,

In the AMAC guff for their 1923-1924 range of carburettors they say there was "... a special carburettor made for Douglas "CW" machines. This is known as the model "T. 30. V.D." ..." Drawings and specs attached below.

"T" means 7/8" throttle valve, and presumably "V" means vertical, but beyond that I know nothing. I've seen the little 3-4 digit numbers on AMACs but I don't know what they mean.

Re measuring jet size. I have a set of extremely small number drills that are ideal for the job, but there is a cheaper and easier way. If you can find an appropriate sewing needle (a darning needle is good - I haven't told anyone where I find mine, but another member of the household looks after it for me), you can gently insert it in the jet, mark the spot where it comes to rest, and measure the diameter of the needle at this spot with a micrometer. Easy to compare jets because the needle will drop deeper into a larger jet.