GL1000 Float Bowl Gasket Issue

This Advisory issued: May 6, 2008

(notice sent via monthly eNewsletter dated May 6, 2008 to 6,000+ email recipients – including every customer who’s ever made a purchase at Randakk’s Cycle Shakk)

Honda GL1000 float bowl gaskets are one of the few items in my GL1000 Master Kit that I do not manufacture myself.

Very recently, I just became aware of an isolated problem with certain Honda GL1000 float bowl gaskets including some that were used in some of Randakk’s Honda GL1000 Master Carb Kits in 2008. I have worked very hard with experts and my suppliers for a solution…which I now have.

I have been buying these float bowl gaskets mainly from K&L Supply. The short version of the story… K&L sources these GL1000 float bowl gaskets from a variety of Japanese suppliers – principally Keyster and Napco. The Keyster gaskets are laminated with an integrated layer of fiber reinforcement to provide size / shape consistency which prevents distortions in use. The Napco version does not have this fiber reinforcement and are made from a different type of synthetic rubber.

Making the story even more complex is that K&L sells both versions simultaneously and both Keyster and Napco are actually “middlemen” that source their actual manufacturing “lots” via multiple manufacturing partners. In any case, I’ve used both Keyster and Napco float bowl gaskets for years with minimal issues. Both types of gaskets are certified for use with “normal” gasoline blended with ethanol…like E10 or E15. Both Keyster and Napco market their wares under a variety of brands and private labels.

For whatever reason, some portion of the last batch of NAPCO gaskets K&L received and shipped to me seems to be overly reactive with gasoline…possibly susceptible to ethanol (or other oxygenating agents) and sometimes swells when exposed to fuel. The problem is that occasionally the gasket can swell to the point that float operation can be affected. The symptom is sudden, severe flooding in recently overhauled carbs that performed perfectly when first put back into service. The curious thing is this seems to occur in isolated cases…most are fine.

Other contributing factors based on my research:

  • The problem seems to originate in areas where ethanol blends are more prevalent and have higher concentrations.
  • Slightly under-torqued float bowl screws contribute to the problem, This permits the gaskets to “creep” inward when the clamping pressure is too low. I realize that this is a dangerous thing to mention as these screws are easily stripped!
  • Slightly mis-aligned float …when splayed outward, they are less tolerant of gasket “creep”
  • One case involved the admitted introduction of forbidden E85!

In any case, this is what K&L has done for me. Their R&D Technical Director and his team worked very hard to understand and resolve this issue. They agreed that there was a problem. They duplicated the problem themselves. So have I. Curiously, some batches of fuel (from different gas stations) that I tried did not cause the swelling which makes me certain that some aspect of fuel composition is the culprit.

K&L has expedited a shipment of improved, reinforced gaskets to me. The engineering and pattern is superior to OEM spec. K&L even changed to a different part number at my request to make sure that everyone was clear on what they were shipping to me. 

(10/1 /2008 edit: K&L has dropped the NAPCO product and the old part number altogether.  Unfortunately, other venders still sell this inferior product.)

If you purchased a Randakk’s GL1000 Master Carb Kit or Honda GL1000 Float Bowl Gaskets between January 1, 2008 – April 30, 2008, there is a slight chance you may be affected by this problem. If you have experienced flooding in recently overhauled carbs that performed perfectly when first put back into service and you can positively rule out any float valve issues (the most probable cause of flooding), please contact me for assistance. Otherwise, no action is necessary on your part.

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