Carburetors

May 18, 2016
Polished domes in Mass Finishing Machine
June 2012
Originally a MGTC woulda had H2 carb, but a five speed we decided to up that to bigger carbs.  We are going to use H4, a little bigger, and modify the intake manifold, to fit.  This carb setup is unique.  THe throttle shaft return springs are that of MGTD.  THe MGTC ones, we had, - it has a "Prewar" look, but the way they work (with the bushing, and spring...) we didn't like.  We used a right/left hand spring (like MGTD) on the throttle shaft.  But We are also using the TC slow running arm.  There is no cam (like a TD/TF) to push the jet down/choke.  
Further news, Joe showed me how to do the carburetors.  Explaining how to center the jet, and the "gypsy" way it works.  THe jet always gets tight, with the final tweaks of the nut (AUC #) tightening.  
Notes:  
Once the body is clean and shaft/Butterfly is installed.
-Install the lift pin. 
-Make sure piston and dome move freely (in position as fitted to carb).  Piston Spring AUC 4387.  
-Use proper needle, GJ for this carburetor.  It's a MGTF needle.  We're using a bigger carburetor on the TC, but using TC/TD type linkage.
-Screw on dome with piston to carb body. 
-Clean Jet housing inside with wire brush/wire brush with Scotchbrite to clean the inside.  No remains from previous cork/packings. 
-Make sure Jet Housing Nut doesn't have too much "wobble" or "Play".  Screw on all the way.  
-Clean Upper jet housing piece.  
-Quickly place the jet into the jet housing, with jut and upper jet housing assy, and you want the jet to stick out the top just a little.  (See pict)
-Using a fine file, file the top of the jet housing, get a nice even flat surface.  Can be done on jet adj nut too.
-Slip AUC 2117 (Aluminum curved ring) onto AUC # nut.  
-Put AUC 2118 onto AUC #.  Using a screwdriver lightly place MotorOil (lubricant) on the cork rubber. and on the threads of the large nut.
-Push Jet housing through ^ assembly with an AUC 3233 thin washer.  
-Place Jet through ^ assembly.  
-Dip two jet cork packing seals (AUC 2120)  in motoroil, and push on 1 jet cork seal, then a brass cup (AUC 2119) Curved side facing the cork, Flat side facing the spring.  THen put on spring (AUC 1158), then another brass seal (AUC 2119), and another cork seal (AUC 2120). Push the upper jet housing onto the jet, PLace washer AUC 2122 between the jet assy and the carb body and screw jet assy onto body.  
-Holding the carb, once you got the jet assy fixed the the body, hold carb body up, so the piston is vertical.
-Use your finger to push up the piston, and let it fall, and you want to hear the "THUMP" Sound,- ALWAYS!  
COntinue to tighten the large jet assy nut, Simultaneously let the piston fall, and push the jet in and out, and in and out.
-You want that sound of the "thumP" as well as the jet to move nice and free
-it tends to bind/ become tight with the final turns of the tightening of the nut.  Which is a bitch.  which is the "gypsy" of this process.  Try coming off the nut, let the piston fall, move the jet up/down.LIghtly hit the jet assy on top/bottom,  
-It's frustrating.  If need be attach the choke mechanism and see how jet feels.  
-Jet/Choke assy might feel a hell-of-a-lot better the next day, when the cork-jet-seals have taken their shape.
-Attach proper choke arm to jet with a clevis pin and cotter pin.  Cotter pin might need to be cut short.
-Attach AUC 4667 return spring from body to choke arm.  
-Attach proper choke bracket from body to choke arm using clevis pins and cotter pin.  
-Float bowl will only fit one way, and look correct.  
-Using anti-seeze compound, apply to Float bowl Screw.threads and w/o the bowl screw into body.  
-Use 2 AUC 5027 fibre washer with a AUC 5026 washer in between onto screw, then float chamber then fivber washer AUC 2130, and screw onto the body.  Make sure the throttle arm can be open/turned and it won't hit the float bowl.