Air Cut Out Valve Kit


Information and questions on GL1200 Goldwings (1984-1987)
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EngFarmer
Posts: 3
Joined: Thu Sep 28, 2017 8:17 pm
Location: Fenelon Falls, Ontario, Canada
Motorcycle: 1986 GL1200A Aspencade, 1970 BSA Lightning, 1972 Honda CB350, 1969 Yamaha DT-1, 1982 Yamaha XJ650RJ Seca, 1950 Velocette LE

Air Cut Out Valve Kit

Post by EngFarmer »



Hi all..this is a first post for me. I am rejuvenating an 86 Aspencade that only has the air cut out valve on the underside of the intake plenum (no other pollution control stuff). It has good compression (180 to 190 psi) and runs smoothly at idle after warm up and appears to have good power without hesitation. Starting required full choke and some coaxing as if there was an air leak somewhere, and there was some misfiring during the first couple of minutes of warm up. Having read that the air cut out valve might cause these symptoms I purchased a kit to renew it. The kit contains 3 pieces; the diaphragm, a spring, and a small rubber ring of rectangular cross section...not an o-ring.


My question is...where does the rubber ring go? There was not one in the valve when I opened the cover. The instructions that came with the kit say to refer to instructions in a repair manual (Haynes, Clymer, Honda etc.) The Haynes manual says nothing about there being a rubber ring and the Honda parts diagrams that I have found online do not list such a part. I contacted the vendor (the source of an old article detailing the problem) and they don't know either since the author of the article is gone now.

The ring does fit well on the nipple of the valve, and would perhaps function to limit the amount of lateral movement if the diaphragm caused some tilting of the nipple during operation. However the tilting would have to be quite severe to have the ring contact the side of the bore it moves within. There does not appear to be any location in the valve housing requiring a rubber seal.

It will probably run without the rubber ring installed and perhaps it is not needed on this model, but any insight would be much appreciated. Thanks.



GWClint
Posts: 12
Joined: Sun Sep 10, 2017 7:14 pm
Location: Strathmore, Alberta ,Canada
Motorcycle: 1985 Honda Gold Wing LTD

Re: Air Cut Out Valve Kit

Post by GWClint »

EngFarmer wrote:
Thu Sep 28, 2017 10:30 pm
Hi all..this is a first post for me. I am rejuvenating an 86 Aspencade that only has the air cut out valve on the underside of the intake plenum (no other pollution control stuff). It has good compression (180 to 190 psi) and runs smoothly at idle after warm up and appears to have good power without hesitation. Starting required full choke and some coaxing as if there was an air leak somewhere, and there was some misfiring during the first couple of minutes of warm up. Having read that the air cut out valve might cause these symptoms I purchased a kit to renew it. The kit contains 3 pieces; the diaphragm, a spring, and a small rubber ring of rectangular cross section...not an o-ring. air cut off valve kit.jpg

My question is...where does the rubber ring go? There was not one in the valve when I opened the cover. The instructions that came with the kit say to refer to instructions in a repair manual (Haynes, Clymer, Honda etc.) The Haynes manual says nothing about there being a rubber ring and the Honda parts diagrams that I have found online do not list such a part. I contacted the vendor (the source of an old article detailing the problem) and they don't know either since the author of the article is gone now.

The ring does fit well on the nipple of the valve, and would perhaps function to limit the amount of lateral movement if the diaphragm caused some tilting of the nipple during operation. However the tilting would have to be quite severe to have the ring contact the side of the bore it moves within. There does not appear to be any location in the valve housing requiring a rubber seal.

It will probably run without the rubber ring installed and perhaps it is not needed on this model, but any insight would be much appreciated. Thanks.
Sorry I don't have an answer to your question, but I have a question for anyone reading this , what is the function of the air cut of valve and what happens if it is not functioning properly?

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virgilmobile
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Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
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83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Air Cut Out Valve Kit

Post by virgilmobile »

I also did not use the o ring.I kept it OEM.
The purpose of this valve it to open during decelleration...closed throttle...high vacuum...and eleviates exhaust popping.
They generally quit in the shut position..Popping in the exhaust.
I suppose that they could be stuck open as well but not likely.Too much spring pressure on it.
Just be sure the valve travels smooth in the bore before you button it up and look at the rubber attached to it.

EngFarmer
Posts: 3
Joined: Thu Sep 28, 2017 8:17 pm
Location: Fenelon Falls, Ontario, Canada
Motorcycle: 1986 GL1200A Aspencade, 1970 BSA Lightning, 1972 Honda CB350, 1969 Yamaha DT-1, 1982 Yamaha XJ650RJ Seca, 1950 Velocette LE

Re: Air Cut Out Valve Kit

Post by EngFarmer »

Thanks for the information and advice. I did clean out the recess housing the sealing disc by flushing with carb cleaner and quickly drying with compressed air before I re-assembled (with the ring on the tip of the diaphragm) and the starting is considerably improved ...so I think the valve is functioning as intended. Now the bike just needs a good workout when weather and time permit.



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