GL1000 CV Slide / Cap Variations

This material is covered in my GL1000 Carb Rebuild Video, but just in case you haven’t made that great investment… 

The plastic “buttons” on the GL1000 carb tops are not separately replaceable. They are swaged into the tops during manufacturing. Here are your options for a broken carb top plastic “button.”

  • Pete Boody has developed a nice repair option.
  • Repair with epoxy (clear looks best and can be buffed to achieve a nearly original looking sheen). Do this off the bike and take care not to block the tiny vacuum transfer port in the cap.
  • Replace with used cap and CV slide. These are matched pairs…machined to a very tight tolerance and weight matched by the factory…never mix and match slides and caps.
  • New OEM cap/slide/needle assembly…very spendy.

All GL1000 carb caps caps are functionally equivalent (except for clearance matching). Caps and CV slides are matched pairs machined to a very tight tolerance and weight matched by the factory. They should never be interchanged.

There are actually 3 types of CV slides fitted to the 5 years of production on GL1000s. These are shown in the pictures below. Never interchange CV slide types as this will affect cylinder balance and introduce tuning problems!

GL1000 CV Slide Caps

75 models have a “scalloped” cut-out on bottom surface of CV slide (note brass insert)

’75 design design permits slightly better flow at wide open throttle

Honda GL1000 CV Slide / Cap Variations

’76 – ’77 models have a CV slide with flat bottom*

*Some ’76 -’77 CV slides have brass inserts and some do not. They are functionally equivalent.

Honda GL1000 Slice Cap Variations

’78-’79 models have a CV slide with radiused bottom edge + Keihin reverted to brass inserts 

More on the issue of fit…

The close tolerances are especially critical in the CV slide center “piston” to cap “bore” aspect. This area is the source of most CV slide binding and sticking and this is where your cleaning / polishing efforts should be concentrated. The clearance between the outer wall of the cap and the CV skirt is much greater. However, most amateur mechanics erroneously focus their cleaning / polishing efforts there. 

CV slide center cleaning & polishing

Blue arrows in the picture above show where you should focus your cleaning / polishing efforts

Take care to keep small relief port (yellow arrow) clear

Note to Restorers Regarding “Correct” Cap Orientation

Carb caps can be mounted in one of two different orientations with respect to the Keihin logos. Either way is fine. They are functionally equivalent.

Hard evidence is somewhat conflicting, but the consensus of opinion for “correct” restorations (and my practice) is to mount the caps so that the cap logos are right side up on the left carbs (carbs #2 and #4) and upside down on the right carbs (carbs #1 and #3)…as viewed by the rider in riding position.

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