Hi,
I have recieved the alternative CD175 CARBS, but struggling to work out what type they are. Apart from the obvious (CD175) the choke mechanism operates a bar that raises in the housing lifting the needle approx .8cm.
The main reason for enquiry, I have (only on one) near the adjustment screw a brass right angle block with a small guage brass pipe approx 3cm long, i have no ideas what this is for. Stupidly did not take photo before i put them on, will however try to take picture.
Difficult to say without seeing it but the first thing that occured to me is whether it’s a DIY method of checking the fuel level in the float chamber.
Re Identiying the new carbs, I was going to suggest buying a copy of the Haynes Stromberg book - until I had a look on Amazon. ?88 new! Even a secondhand one covered in oily fingerprints is going for ?35. If you’re ever in my part of Oxon (Thame) you’re welcome to use mine to check the carbs.