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Can anyone recommend me a carb needle?
I have a standard 850 bottom end with a skimmed 12g295 head, single 11/2 hs4 carb, pipercross air filter, mini spares Inlet manifold, rc40 exhaust.
It's currently fitted with an ABA needle as this is the nearest equivalent I could find to the old E3 recommended by Mr Vizard but I'm not sure this is right. I also have a AAA needle which is quite a bit richer.

Get this spreadsheet here:
http://mk1-performance-conversions.co.u ... l_carb.htm

The spreadsheet has automatically chosen some swing-type needles
which are very similar to fixed type E3.
You can click it a couple of times to make it bigger,
Click the "Back" button on the browser to return to the post.

Ian

Thanks for that Ian.
It looks like I'm quite close with the ABA needle.

As well as needle, the dashpot spring also affects the mixture significantly. Which spring are you using?

And 'vizardising' a HS4 carb bore weakens off the mixture at high rpm high load conditions. Enough to burn out exhaust valves if you don't alter the needle...