Aisan Rebuild

These Aisan rebuild instructions are generic to the Aisan carburetor.

Instructions are specifically for our kit K327
1973-79 Corolla 12001973 Corolla 1166 1972-70 Corolla 1166

Tip: Take photos along the way so you can refer back if needed.

Tip: Use a cookie sheet to hold the parts. This will keep the small parts from rolling off.Tip: Save all small parts and clips. Our kits come with all that are necessary but they are easily lost.
Cleaning: Do no soak any plastic, or rubber parts. Soak in Simple Green for 2 hours. Be careful or the Aluminum will get discolored if left too long. Carburetor cleaners from your parts store will also work. Follow the directions on the can.

Wash off all chemical – use hot water if possible.Blow out all passages with compressed air. Check each passage to make sure the air is going all the way thorough.

Remove the top

Aisan Rebuild
  • remove fuel pipe – #3
  • remove pump connecting rod – #16
  • remove adapter assembly – #10
  • remove top screws – #19
  • remove fast idle rod – #18
  • If the top doesn’t want to come off easily, rap the side of the top with a rubber hammer. Be careful not to hit a piece that can break off.
  • Be careful that you don’t turn the float bowl upside down. Parts will fall out.
Aisan Carburetor Parts
Aisan Rebuild
  • pull float pin #21 & float #22 – Do not soak float, or any other plastic piece.
  • remove needle & seat #23 – Located under the float tab. The seat screws in a counter clockwise direction.
  • remove power piston #28 – There is a power piston screw holding the piston down beside the piston and under the float as shown.
  • remove accelerator pump #24 – Unscrew the bolt #15 holding the pump lever #16 to the top. The pump can then be pulled out.

Tip: polish the power piston using a wire wheel. Polish the piston hole (well) with crocus cloth if it has any roughness at all.

Aisan Rebuild
  • Remove the accelerator pump spring #31, or #3 as pictured.
  • Remove the check weight and check ball #32 & #33. Turn the bowl over and the parts will drop out. The larger of the 2 check balls go into the main discharge hole. Do not lose the check weight. It is not available and has a hole in the center to allow fuel through. If you lost it, then add a 2nd check ball to the hole.
  • Remove the retainer and check ball under the pump return spring #3. The retainer is spring loaded and easily lost and are not available. The small of the 2 check balls go in the bottom of the pump well.
  • Remove the primary & secondary venturi #48 & #45 by removing the venturi screws #44.
  • Remove the secondary jet #38. – unscrews count clockwise. Original was silver colored. Be sure to keep track of which jet goes in which hole. They are not the same size. Use a gasket on both jets.
  • Remove the primary jet #42. – unscrews counter clockwise. Original was brass colored.
  • Remove power valve #37 – unscrews counter clockwise. No gasket on the power valve.
  • Remove idle jet #36 – NOTE some Aisan carburetors have 2 jets that screw into the bowl and they look alike. Be sure not to get them mixed up.
Aisan Rebuild
  • Remove the A.S.S. valve #7
  • Remove idle mixture screw #55 – when installed screw in clockwise until gently seated, then turn out 2 turns. Fine tune once engine is at operating temp.
  • Remove the throttle body screws #50
Aisan Rebuild
  • Remove the throttle body screw #51 & #52 – One is hollow. Don’t get them mixed up.

Clean your parts are described above

Assemble in the reverse orderIt helps to spray the gaskets with silicon spray lubricant.

Run your finger around the edge of the leather cup to break any sealer it may be coated with.

Apply 2 drops of oil to the leather cup. It may take a few starts before the pump is fully expanded.

Aisan Float Adjustment
Aisan Rebuild

Nitrophyl & brass float has the same measurement. Measure from the lowest part of the float to the edge of the top without the gasket.
Watch a video about rebuilding the Aisan carburetor.

Updated on 05/11/2021

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