1987 GL1200 Fuel Petcock - one year only - HELP!

[WingMan71]

Has anyone actually taken the fuel petcock on a 1987 GL1200 apart and put a rebuild kit 4-hole disc and gaskets in it?

I'm trying to find out of they use the same rebuild kit parts as a 1984, 1985, and 1986 GL1200 fuel petcock. If they don't, we 1987 owner are just plain screwed if our fuel petcocks spring a leak.

Here's what I've found out so far:

The 1987 fuel petcock (PN 16950-ML8-601) is definitely a different part than the fuel petcock (PN 16950-MG9-005) for a 1984, 1985, or 1986 GL1200.

The obvious things that are different are:

1. The fuel outlet on the 1987 petcock is 3/8" (10mm fuel hose), while the fuel outlet on the 84, 85, 86 is 1/4" (5.5mm fuel hose). So the fuel hoses that fit are not the same. (Not exactly a deal breaker.)

2. The distance between the mounting screw holes is different: the 1987 petcock mounting holes are approximately 46mm apart,while the 84, 85, 86 petcock mounting holes are about 42mm apart. So they won't mount on an '87 fuel tank and vice-versa.

3. The entire body of the 1987 fuel petcock is larger than an 84,85,86 fuel petcock. The 1987 petcock body diameter is 32mm. The 84, 85, 86 petcock body diameter is 28mm. So, they are 4mm smaller.

The 4-hole disc (PN 16955-268-020) that comes in a rebuild kit for the 84, 85, 86 fuel petcock is 20mm in diameter. That's the issue that worries me. Will that disc fit in a 1987 fuel petcock properly, or is the 4-hole disc for a 1987 fuel petcock actually larger in diameter to fit the larger fuel petcock and flow more fuel?

I have a rebuild kit for an 84,85, 86 GL1200 that includes the 4-hole disc (PN 16955-268-020). The '87 fuel petcock is riveted together and not designed to be rebuilt. (Though many other Honda petcocks are as well, but can be drilled out, rebuilt, and reassembled with screws. I've done many that way.)

If I take mine apart and the 4-hole disc doesn't fit, I'm basically screwed. NO one, and I mean NO one has a 1987 GL1200 fuel petcock for sale on planet earth. I've checked all of my many sources, including vintage bike parts suppliers and my "special" one in Norway.

So, has anyone successfully taken apart a 1987 GL1200 fuel petcock and rebuilt it using a rebuild kit for an 84, 85, or 86?

Thanks for any advice or experience on this issue.

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[Rednaxs60]

Check out Straightwings: http://www.straightwings.com/

Found 3 listed.

[WingMan71]

Check out Straightwings: http://www.straightwings.com/

Found 3 listed.

Hello,

Thanks for looking for me! I appreciate that. I have about a dozen vintage parts sites I use, but have never seen that one. They do have a large inventory.

The GL1200 fuel petcocks they have are all listed as "84 to 87 Fuel Petcock", so they clearly don't know that the '87 fuel petcock is a one-year-only part and that the 84, 85, and 86 fuel petcocks won't fit on an '87 fuel tank.

Even so, I'm going to contact them and ask them if any of theirs have a mounting hole pattern of 46mm. If so, that would actually be an '87 petcock.

Thanks again for looking for me. Maybe I'll luck out and one of theirs will actually be for an '87.

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[brianinpa]

I ran into the same issue you are seeing... parts listed as 84-87.

I took mine apart, flipped the gasket over and turned in 180 degrees and put it back together again. Hasn’t been a problem since then. The damaged portion is no longer in an area that seals... something to consider.

[WingMan71]

I ran into the same issue you are seeing... parts listed as 84-87.

I took mine apart, flipped the gasket over and turned in 180 degrees and put it back together again. Hasn’t been a problem since then. The damaged portion is no longer in an area that seals... something to consider.

I have heard that same procedure suggested on another forum. If all else fails, I may just get brave enough to take mine apart and flip/rotate the 4-hole disc gasket and put it back together and pray!

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[Rednaxs60]

When I replaced the o-ring, went to the local hydraulic shop and got the closest facsimile I could, is working well. Here are a couple of pictures regarding the 4 hole gasket and the wear:

Showing wear on the rubber surface

This second pic shows the 4 hole gasket flipped and no wear on the holes:

Cheers

[WingMan71]

Rednaxs60 & brianinpa,

Thanks so much for sharing your experience with the perils of an '87 GL1200 fuel petcock! Really appreciate it. Thanks for the pictures too.

Armed with this information, I'll probably go ahead and disassemble my petcock, flip/rotate the disc, and find a new o-ring to best fit the housing o-ring.

First thing is to finally get myself at least a workbench top drill press to successfully remove the rivets and then drill and tap the holes. I've done this before on other petcocks with a hand held drill and it's not easy. And on those, and extra petcock was not hard to find if I screwed up. Not so with an '87 petcock.

PS) Did either of you ever measure the diameter of the 4-hole disc gasket for the '87 petcock when you had it in your hands? That would be a good dimension to know. The diameter of that disc for an 84, 85, or 86 petcock is 20mm. i'm guessing the '87 disc must be at least 4 or 5mm larger in diameter.

Wish me luck! Thanks again.

Bob

[Rednaxs60]

No worries. Drilled out the rivets and used a small bolt with a nyloc nut as shown in this picture. Used a hand drill to remove the rivets.

To get a good fit when installing the fuel shut off valve, put the nuts on the outside as shown here:

Cheers

[WingMan71]

No worries. Drilled out the rivets and used a small bolt with a nyloc nut as shown in this picture. Used a hand drill to remove the rivets.
Fuel VV Rebuilt and Put together - 2.jpg To get a good fit when installing the fuel shut off valve, put the nuts on the outside as shown here:Fuel VV Final - 2.jpg

Cheers

"Hey", I said to myself. "That's not the same fuel petcock that's on my '87 GL1200A."

Then I see your avatar. You've got an '85 GL1200 LTD! Your fuel petcock is even MORE rare than mine!

No doubt that you HAD to rebuild yours!

[brianinpa]

First thing is to finally get myself at least a workbench top drill press to successfully remove the rivets and then drill and tap the holes. I've done this before on other petcocks with a hand held drill and it's not easy. And on those, and extra petcock was not hard to find if I screwed up. Not so with an '87 petcock.

PS) Did either of you ever measure the diameter of the 4-hole disc gasket for the '87 petcock when you had it in your hands? That would be a good dimension to know. The diameter of that disc for an 84, 85, or 86 petcock is 20mm. i'm guessing the '87 disc must be at least 4 or 5mm larger in diameter.

Wish me luck! Thanks again.

Bob

I have a bench top drill press but I just used a hand held drill. The rivets are the kind that you only need to remove a small bit of it and then use a drift punch and drive the rest out. Oh and I never measured the size of the holes

[leakyroof58]

Unless your trying to maintain a pure-stock
GW, just go to the local lawn/garden center
and get a fuel shut-off valve for a lawn tractor.
That's what I did, after finding out I went 70
miles with a "closed" petcock. I put mine
about 2 inches downstream from the original -
easy to get to, and hardly visible.........

[WingMan71]

Unless your trying to maintain a pure-stock
GW, just go to the local lawn/garden center
and get a fuel shut-off valve for a lawn tractor.
That's what I did, after finding out I went 70
miles with a "closed" petcock. I put mine
about 2 inches downstream from the original -
easy to get to, and hardly visible.........

Already checked that out. They are definitely available, even 90 degree ones which would fit better in the fuel line under the existing petcock on a GL1200 as it bends around the corner and into the fuel filter, but none available with 3/8" fuel fittings. I can get one tomorrow with 1/4" fuel fittings, but I don't want to reduce the fuel flow to the carbs that much if I can help it. (That's why the petcock on an '87 has larger internal fuel passages and a bigger fuel outlet fitting in the first place.)

Also want to keep my bike as original as possible since it's a show quality bike and has won several awards a bike shows, including taking first-in-class at Wing Ding 37 in Huntsville Alabama a couple of years ago.

I'm working with some suppliers of petcock rebuild kits sourced by Mikuni (the carburetor manufactuer) in Japan. We're particularly looking to see if there is an existing kit for any other motorcycle or ATV that has the proper sized 4-hole gasket to fit in an '87 GL1200 petcock. I'm hopeful that we'll find one.

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[WingMan71]

Hah! NEVER GIVE UP ! ! !

I found a rebuild kit for some Honda ATVs that fit the '87 GL1200 fuel petcock and can be used to rebuild it!

I've put the info in a new thread so the admins can make a sticky out of it if they want to.

See this thread for the info:

viewtopic.php?f=5&t=42048

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