Awesome, thanks heaps for that Benny. I'll go buy a few jets and try them out.

Thanks for the ideas guys.

Clay

OK, I just pullled mine down to check for jet sizes. This was running on an A12 with a rather warm cam.

jet---------primary / Secondary
idle--------55--------50
main-------130-------135
emulsion t--F50-------F45
pump------50--------n/a mine is a single nozzle type, there are dual outlet available
Aux V------4.5-------4.5

hope this helps

cheers
benny

Thanks guys for the assistance.

The carby is just the manual choke one, DGV-5A.

The idle jets are (ones accessible from outside on the body??):45/50

The other option I can think of is maybe the main air jets are too small?

The idle mixture screw is only 1/2-3/4 of a turn out from when the engine stops. The idle screw is at the minimum setting to keep the car idleing.

The plugs have a black carbon residue, bit too rich?
I cupped the throat and the engine wanted to die without any improvement first, so I hope that rules out any vacuum leaks in general.

I have adjusted my timing as well as part of this process, which I hope is all ok.

I understand that it is a little harder to tune with a larger cam, I just haven't played around too much with these carbys before. It is a relatively new carby too.

I might try and order a few different jets and have a play, if that's what is still seems to be?


Appreciate your help guys.

Clay

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Also check your ign timing, if you have had things apart you may have this wrong.

You should be able to get it to idle around 1000rpm no problems.

Check the Spark Plugs, they could tell you a little about the mixture, they will be a guide to know if it is a mixture problem, it could also be a vacuum leak maybe?

I'm not sure how similar these are to DCOEs, but with DCOEs the idle jets control progression and the mixture is more directly controlled by the volume screws on the body.

First point of call would be to adjust any idle screw settings, if there is such a thing on this carb (surely there is?).

However if you're rough all the way to 2800 then it could be one of two things... the idle circuit is too rich due to the adjustment screw, and as a result it isn't cleaning up until 2800rpm.... OR progression is too rich due to idle jetting and you need to correct it.

Play with adjustments first, otherwise change the idle jetting.

yep, the idle jet controls the fuel metering for idle and progression ccts. What are you running at the present? On the 32/36 setup I was using, I had an idle jet size 55.

BTW, is your carb a DGV-5A, DGEV or DGAV. if it is one of the later two, then your auto choke may not be adjusted correctly. worth checking out

Hi guys,

I have a freshly rebuilt engine and am having what I expect is a carby tune issue. I have a 32/36 DGV down draught. I can’t get it to idle below 1500 rpm and it splutters and coughs from 1500rpm till about 2800 rpm, then it comes good. Does this sound like a potential idle jet sizing issue? Or could it be something else?

Just curious to know if I am barkin up the wrong tree.

Thanks guys

Clay