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SU Jets

Posted: Thu Jun 09, 2022 8:22 pm
by Mad Mart
How do you tell what type/size SU jets are if you just have a random jet in your hand? Needles are easy as they have their codes stamped on them.

Re: SU Jets

Posted: Thu Jun 09, 2022 9:12 pm
by yorkshire_spam
IIRC the jets vary by the opening in the end. 0.09", 0.10", 0.125"
HIF38/HS2/HS4 (0.090), HIF44/HS6 (0.100), HS8 (0.125)

Re: SU Jets

Posted: Thu Jun 09, 2022 9:31 pm
by marshman
Simple. (For HS series jets)

0.090" have no groove around the top of the jet
0.100" have one groove around the top of the jet
0.125" Have two grooves around the top of the jet

A red jet head moulding is for horizontal mounted carbs and a black moulding is for carbs mounted at an angle. (generally, though there also white mouldings for some carbs)

The flexible tube should also have one or two coloured bands on it. These and the colour of the moulding at the bottom of the jet tube (black or red) will identify the part number of the jet.

So a standard sprint AUD9105/6 jet will have 1 groove, have a red jet head moulding and either a yellow band for the AUD9105 rear carb jet or orange for the AUD9106 front carb jet.