How to Rebuild your Petcock

Step-by-step tutorials on how to maintain and fix your GL1500
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How to Rebuild your Petcock

Post by wingdings » Thu Jan 26, 2017 3:20 pm

The petcock is one of the more over looked items on a goldwing when it comes to maintenance - here is a quick guide - how to both check it repair it and rebuild it too .


Like any other malfunctioning part, there are a few different symptoms.

One is that the engine will run for a short time and then die. It will not immediately restart but will restart in a minute or two.

Another is the engine bogs down while traveling along in fifth gear and just will not accelerate. But, if you down shift and then crank on the throttle it will pick up and run great at high RPM's but then bog back down again shortly after you up-shift.

Another indication is there will be fuel collecting in the cavity where the fuel cap is but you probably can not see where it is coming from

There are other symptoms but to troubleshoot the petcock, there is a procedure in the service manual to follow. It involves using a small hand held vacuum pump like the Mity Vac. The procedure is in section four of the manual. The petcock is called an Auto Fuel Valve. It is a simple process and should take only a few minutes of your time to test it.

(special thanks here to mike b . for the above paragraph .)


first remove the top shelter to gain access to the petcock - once the top shelter is removed you should be able to see the petcock - remove the vac line at the top of the petcock - and fit the vac pump via a rubber tube to the end of the petcock as shown in the pic 2)- below follow instructions in the picture to the letter

Top shelter removed petcock now showing

The shop manual method



Remove the top shelter - disconnect the fuel filter pipe - just where it connects with the top of the filter - Then disconnect the second pipe at the petcock end - ( I left the fuel pipe on the petcock end mainly because of the tight bend found it easy then too refit later doing this way) .

Next - remove the vac tube from the top of the petcock - Then remove the gas cap and place a clean shop rag in the hole ( This is to prevent any objects falling into the tank ) carefully lift up the plastic tray away from the top of the petrol tank pull it to the right it should fold over - remove the rag and replace it back in the top of the gas cap hole .

Next find a good fitting Philips screw driver that fits snug into the bottom two screws on the petcock body one screw is easy to get at the other is a little harder but is do-able with care - when these two screws are out the petcock will be released in one unit leaving the bracket behind .

You could just remove the bottom screw which sit underneath the plastic tray - however I found it hard to get at and a very big chance of it dropping down into the engine bay not good at all .

Once you have removed the petcock unit - Take the unit to a clean well lit area - holding the petcock firmly in one hand loosen up the top two remaining screws - hold the two half's together as there is a spring inside carefully remove the last two screws and release the top off the petcock - lay the parts out on a clean surface inspect the rubber diaphragm for rips or tears and check the weep hole at the bottom of the petcock mine was goo'ed up with muck and stuff .

Next - clean all the parts up - I used brake cleaner on mine -



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Posts: 62
Joined: Wed Jan 11, 2017 5:25 pm
Location: Ocala,FL
Motorcycle: 1997 GL 1500 SE
2006 GL 1800

Prior Motorcycles owned
1965 Honda CB 50 1965 - 67
1967 Honda CB 160 1967 - 68
1968 Honda CB 450 1969 - 70
1974 Honda CB 750 1977
1978 Honda CB 750K 1977 - 80
1985 Honda GL 1200 1994
1995 Honda GL 1500 1994 - 99

Re: How to Rebuild your Petcock

Post by jim34481 » Sun May 14, 2017 9:35 am

I had a strong gas smell after shutdown on my 97 GL 1500 SE when I parked it in the garage with the door down. After some research here on GWdocs, I decided to replace the software in the auto fuel valve with parts from cyclemax and this how to article. It took me 2 hours to complete the job with most of that being used to remove/install the interference to get the valve off the bike. It did indeed correct the problem. I have used several "how to" articles posted on this site with great success. Thank you for taking the time document these DIY articles.

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Motorcycle: 1999 GL1500 Aspencade
1988 GL1500 (sold 4/17)

Re: How to Rebuild your Petcock

Post by Corkster52 » Sun May 14, 2017 11:30 am

Just ordered the kit from Cyclemax to rebuild mine. Thanks for the great info here!

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Location: mells , England, United Kingdom
Motorcycle: Honda Goldwing gl 1989

Re: How to Rebuild your Petcock

Post by wingdings » Mon May 15, 2017 3:11 am

Good morning there !! to you Jim glad it helped you sort out the problem too !! - I did mean to add another possible cause to the problem to - some time the fuel cap can cause the bike to cut out inside there there is a rubber diagpham and a spring over time its sticks shut and causes a negative vacuim in the tank - you will notice this when you get down to half a tank of fuel the bike will stall - however fill the tank back upto full the problem will go away !! if this happens to you then - try this ( see links below )

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Location: hammond L.A.
Motorcycle: 1993 gl1500a aspencade

Re: How to Rebuild your Petcock

Post by » Thu Jan 25, 2018 6:13 pm

just did mine 93 aspencade it was leaking runs great! and no gas smell.

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Joined: Sun Apr 29, 2018 1:14 pm
Location: New Vienna Ohio
Motorcycle: 1995 gl1500 honda

Re: How to Rebuild your Petcock

Post by dpilotextreme » Sun Jun 03, 2018 6:25 am

You should use a JIS screwdriver
phillips will round out the cross cut in the screw head
All Japanese products use JIS screws

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