My Petcock Solution ($27.08 All new parts)

Hey, this petcock solution seems great, but what not very many people are talking about is the fact you have to turn the gas on and off every time you ride. Why can't you just install a 5 dollar on/off switch from the hardware store, you'll accomplish the same thing.


I decided to install the system! Works great (and looks better than a lawnmower shut-off valve)

 

I just installed the pingel adapter and Z1 petcock on my XJ550R. The only problem I ran into was that I split the paper gasket when I torqued it down. This left me with no more Hylomar and no gasket.

So I then had to try and clean everything up, go to the all night auto parts place and buy some cork/rubber gasket material and some #2 flexible gasket maker and start over.

It seems to work now, but i need to do some more clean up around the base of the adapter.

 

While I was gettin set up for the KREEM tank coating job on my ride, was cleaning up the petcock and discovered the vacuum valve. Said to myself "Well that's tricky, but just more stuff to go wrong, so I just replaced the diaphram valve with a gasket. Then I'm saying why was it there in the first place. I was gonna put a second inline shutoff in the gas line but now I think I'm gonna go your route.

Good post

 

The holes on my '85 xj700 tank are 46mm c/l. That's 1 26/32 inch or 1.8125inch that converts to 46mm.

 

I had a talk with the guy at Z1. He can get the 46mm adapter plates but not till after Jan 1. Google "petcock adapter plate 46mm". There are quite a few options out there. Did order the petcock itself from Z1. He seems to be a good dude

 

Does anybody know what size adapter plate a 82 550 needs?

 

Hey Littleburg, the 550's use a 34mm spacing of the petcock mounting holes.

I do have these complete sets in stock:

http://www.xjbikes.com/Forums/viewtopic ... t=135.html

fp17) Aftermarket Complete ON-OFF-RES FUEL VALVE. Not really a "petcock" in the XJ sense of the word. Yamaha designed their petcocks to be a very clever "automatic" fuel supply valve, meaning it has to have engine vacuum for it to function. Great idea (when it works) because it allows us to basically "set it and forget it". Bad news is that when the seals go bad, or as age wears the internal components, it can become a really bad idea, since it will leak fuel into the carbs when it's not supposed to, leading to flooded carbs, fuel in the crankcase, spun bearings, etc.

This true fuel VALVE is either ON (in either the standard "ON" or the "RES"erve positions) or it's OFF. And it doesn't depend on engine vacuum, just gravity. So it won't ever leak or pass fuel in the OFF position. That's the good news. The bad news is that you have to remember to turn it on or off manually (as in every time you start your bike up or shut it down) or, instead of blaming a faulty petcock for your resultant problems, you'll have to blame yourself!

Once installed, this unit fits and looks somewhat the same as an original XJ-series petcock, what with the chrome faceplate and selector lever. It obviously has no vacuum nipple, only a rear-ward facing fuel outlet, which means you will need to remove your petcock vacuum line from the #3 intake manifold boot nipple and replace it with a rubber block-off cap plug. This fuel valve uses the same size fuel line as original.

You also must use a adapter plate on the bottom of your fuel tank that this fuel valve screws into, and the brass-mesh, in-tank fuel filter (included with this valve) is actually larger than the opening in the bottom of the gas tank (just ever so slightly), so you'll have to grind the tank opening with a dremel tool or steel file to allow the filter to go into the opening. Our complete HCP630SET (below) includes a bolt-on grinding template so you'll know exactly how much metal to remove.

All-in-all, this is a both a great value and a fine idea. It forever eliminates the dreaded "leaking petcock" problems associated with 20+ year old factory petcocks for a price just slightly more than what it costs to rebuild a factory petcock. On the downside, you will have to remember to turn this unit off or on every single time! And, once you modify your tank (by enlarging the petcock opening), an original petcock will never seal up properly to it again (or, not without alot of effort on your part to "shrink" the enlarged hole!).


550/650 (except Turbo)/750/1100 models:

HCP630SET34 Complete aftermarket FUEL VALVE KIT, contain everything you'll need to replace a factory XJ550/650 (except Turbo)/750/1100 petcock. Includes the HCP630 fuel valve, the HCP99 adpater plate, the HCP632 mesh in-tank fuel filter, the HCP1281 tank grinding template, a single HCP81 intake manifold nipple CAP PLUG, and a single HCP542 cap plug PINCH CLAMP.
$ 52.00

HCP630 Aftermarket FUEL VALVE ONLY, as used in the above complete kit. Includes the HCP632 in-tank brass-mesh fuel filter.
$ 25.00

HCP632 Aftermarket brass-mesh FUEL FILTER for the HCP630 fuel valve, filter only.
$ 11.00

HCP99 Aftermarket fuel valve-to-tank ADAPTER PLATE, includes the plate, plate-to-tank mounting screws, screw washers, die-cut plate-to-tank gasket, and a packet of gasket sealer/thread sealant. This adapter plate fits all XJ550/650 (except Turbo)/750/1100 models.
$ 24.00

HCP1281 aftermarket tank opening Grinding Template....a bolt-on thin aluminum plate that has a hole the exact size and placement needed to enlarge the petcock opening hole in the tank to accept the HCP630 fuel valve listed above. Takes the guesswork out of this critical task! This grinding template fits all XJ550/650 (except Turbo)/750/1100 models.
$ 7.00

 

Yes, I just finished this today on my 550. 34 mm is the ticket.

 

Resurrecting a dead thread ;-)

How are these systems working for you guys, still good? No problems??

My current petcock is shot beyond repair, so in a blur one night I ordered one online for 30$.. wrong one ;-( (will see it in the sell forum in the next day or so)... so I went to ebay and found a decent one and ordered that... I am anticipating that it will need a rebuild kit (mine was so bad you couldn't even rebuild it)....

So now I found this thread ;-P.. I am more then willing to re-ebay everything if this solution still works and is good! I actually like the idea of having to turn on/off the gas manually ;-)

anyone? anyone? bueller? bueller?

 

This solution works well; the only drawback is that you have to enlarge the hole in the tank where the petcock enters the tank. Original petcocks use a oval-shaped filter; these use a round screen and that screen is bigger in OD than the width of the stock filter; hence you have to open up the tank hole a bit (with a dremel or a round file). I provide a template so that you have a precise guide for this opening, BUT......once you enlarge that opening int he tank, then there's "no going back" to the original petcock, as it would be very difficult to "shrink" the now-larger hole back to the stock size.

Of course, once you use one of these for a while and get in the habit of turning them on an off, you won't want to go back......

HOWEVER, for forgetful or ease-of-use individuals, the "automatic" vacuum petcocks that came on the bikes are hard to beat, and if working properly, are foolproof.

 

ya, the 'if working properly' part is the catch though ;-)

 

I was doing some rescerch and found this site, looks like the same but a little cheaper.

https://www.partsnmore.com/cat_index.ph ... egory=carb