Honda GL1000 Emulsion Tube Variations

You might consider this item: Randakk’s GL1000 Carb Rebuild Video

Emulsion tubes are perforated nozzles designed to pre-mix fuel and air for subsequent metering by the main fuel jets. Sometimes these are also called:

  • Main jet nozzles
  • Main jet holders

Emulsion Tube Variations

The “froth” created by emulsion tubes improves fuel atomization. In the GL1000, both the main and secondary main fuel jets employ emulsion tubes. Keep in mind that when a bike sits unused for any length of time, these emulsion tubes can get plugged with residues. This will seriously disrupt the air-fuel mixture. Each carb may be affected differently, so the symptoms can be a bit contradictory and elusive. Generally, the lack of air, will cause an over-rich condition on the affected carb(s). Depending on which holes are plugged, you can sometimes get weird, rpm-dependent problems.

There are 2 variations for both the main and secondary main emulsion tubes used in the GL1000 range. These can be intermixed with bad results!

Special note regarding main emulsion tubes:

The tangs that look like screwdriver slots are not actually screwdriver slots, but really distance pieces that positively locate the main jets. One broken “ear” is OK, but when both are broken off – that is bad as it will allow the jet to move from its precisely engineered vertical location.

Emulsion Tube Variations

The main jet emulsion tube above is correct for 755A, 758A and 763A Carb codes (’75, ’76 and ’76 LTD US models).

Notice that there are 5 cross-drilled holes.

Jet Emulsion Tube Variations

The main jet emulsion tube above is correct for 764A, 769A and 771A Carb codes (’77, ’78 and ’79 US models).

Notice that there are only 4 cross-drilled holes.

Emulsion Tube Variations

The secondary main jet emulsion tube above is correct for 755A, 758A and 763A Carb codes (’75, ’76 and ’76 LTD US models).

Notice that there are 5 + 2 cross-drilled holes in a 1-piece brass tube.

2 photos above show the secondary main jet emulsion tube correct for 764A, 769A and 771A Carb codes (’77, ’78 and ’79 US models).

Notice that there are 5 + 2 cross-drilled holes in a 2-piece design…brass tube + stainless “hat.”

Again, these emulsion tubes can be intermixed with bad results! A few aftermarket carb kits include main nozzles that are not 100% correct depending on specific carb code. Always install the correct emulsion tube for your carb code.


Comments

  1. Christopher Barry Rose says:

    Hunting down the 4 hole variety for my 77 has been a PAIN. Seems like every kit made uses the 5 hole varieties and yet claims they are for all 75-79 bikes. Anybody find a good source for replaements? I need two of the 4 hole main tube type.

  2. RACS.LIP@gmail.com says:

    I have a 77 GL1000. I pulled the carbs off to rebuild they are 771A coded would you say thats the correct set up for that year?

  3. I have a 76′ GL 1000 and I found one secondary jet emulsion tube, broken and repaired in a very bad way. I’m from Argentina and there is no manner to find the part. Would you tell me if it’s possible to buy it in US or if you can sell me one of them, at least a used one? The carb model is 758A, so the secondary jet is in one piece.
    Thank you!

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