The carburettor throttle body, including butterflies, idle adjustment, and automatic choke assembly.4.
The float chamber vents into the air horn, which has an opening where the accelerator pump is, that is open at idle.This opening is closed by an adjustable vent washer on the accelerator pump plunger as revs rise.The wheel and tyre combinations were far from great, particularly by today's standards.The 13 inch wheels on the sixes were very narrow at 4.5 inches, as only the GTR got 5.5 inchers.If you can see a circle of wear around the needle part of the “needle and seat��? Make sure you put the wire restrictor back when connecting main body to throttle body.
Don’t use any lubricant on the power valve, or it’s bore in the air horn (top).The top (air horn) gives the appearance of a single throat, but if you look down inside, you will see that there are two throats and butterflies. The carburettor top or air horn, including economiser jet vacuum piston (or power valve), float vent, external choke diaphragm assembly, and choke butterfly.2.The carburettor main body, including jets, float, accelerator pump, and vent.3.A 23-201A&B is 186S Manual, a 23-202A&B is 186S Auto.The earlier version for an HQ 253 manual is the 23-3046, & the later version (Nov '72 onwards) is the 23-3064. The 23-3098 is for the 4.2 (253) V8 auto in HX & LX from July '76 to April '77.Alan Salt's Shed HQSS' Shed The carburettor should have a parts code number on its body.