Fuel Petcock rebuild - suggestions?

[greenbarn]

BTW, I'm sure this did shut off at one time - I had the fuel lines off last year to drain the fuel, and it worked fine at that time.

[greenbarn]

When I took the tank off for other reasons, I noticed it was leaking.  It was a lot more than a drip, but a lot less than full-stream.  A steady trickle, let's say.

Like you I thought it was one of those things you mentioned, and cleaned the seat, etc. but did not help.  Then I ordered a re-build kit, and installed.  This has a new diaphragm, which the plunger/pin with the o-ring (the actual thing that shuts off the fuel) is attached, so this is all new.  Kit includes new spring(I even stretched the new one a tad more - it's significantly stiffer than the original now).   still leaks.  Took it back apart, this time I practically honed the seat surface best I could - it's recessed about 1/2" inside and hard to get to -  back together - still leaks.  I've had this thing apart (it comes apart pretty easy) at least 10 times, perhaps 15.

BTW, my method of testing for leaking is blowing/sucking air thru the fuel outlet fitting by mouth.  I did put it back on the tank once to make sure it does leak fuel, but otherwise I haven't put it on the tank every time.  I've determined for sure it's the plunger/pin mechanism that's leaking, but there is no explanation for it.  If I take the back cover off, leave the diaphragm in place, and I push the little plunger closed with my finger, it will actually close and seal, but it's not getting enough pressure from the spring for whatever reason.

I know the manual valve thing will require remembering to shut it off, but I thought perhaps that's preferable to not knowing if it's shutting off or not.  Here's the rub:  at this point if I were to get it to seal,  unless I find a positive reason for this thing not sealing, I wouldn't want to trust it- you can't exactly see if the thing is working from day to day.

[Troll]

  Going back to a manual valve is going to mean you have to remember to shut off the fuel when you park it at night...I'm thinking that the reason the valve leaked is because there is build up of crud on the pin and seat in the valve, causing it to pass fuel when it's shut off. Did it leak a lot, or just drip? Cleaning the valve seat surface and the pin on the diaphragm, and maybe stretching the spring just a little would probably cure it. Either way, the float in the carb is the final arbiter of fuel level, so if it's ok, then all will be well.  Just a note, but the vacuum valve on my W650 will leak a little fuel around the handle when it's really cold out (below 20 deg F).

[greenbarn]

Does anybody see any disadvantage to putting a non-vacuum controlled petcock on the 800?   The kit I bought did not work on this POS, so I'm looking at a new valve.

New OEM 800 stock valve:  $65-70.  (51023-1260)   (ron ayers, kawasakioemparts, etc.)

New replacement valve for 99 1500 - $25.  (51023-1330) (ebay
This appears as though it will bolt onto the 800 tank.  They both have the same gasket part no. (92055)

The 800 is vacuum controled -ON-RESERVE-PRIME
The 1500 has no vacuum control - ON-OFF-RESERVE

Any reason the 1500 wouldn't work, and be at least as good, or better?  Then it would be less likely to leak through the valve - it's a simpler design, I believe, getting rid of the vacuum.  Course, the reserve level might be different.

[greenbarn]

no we are not big enough, ....

me neither...  I don't think anyone would mistake my size 8W footprint for bigfoot...

[CDNRatMan]

 no we are not big enough, my family reunion is Orangutan Island

[greenbarn]

yer real funny, ratman.

So is that like watching your family reunion?

[CDNRatMan]

  Greenbarn off on a rabbit chase here, but watching TV tonight and they are tlaking about you on the TV tonight, animal planet channel, Finding Bigfoot....lol

ok sorry I am not picking on you but 49 is not around enough to pick on him......oh doe you live near any corn fields? Okhave to go and watch it now.....

[greenbarn]

Thanks, Bake. I much appreciate that.  I've actually got one ordered.  I was considering ebay but I needed a few other things, so I ordered one from JPCycles.   THANKS for the help.  I was planning to post here after I get the kit installed to see how it works.

[David Baker]

greenbarn, Saw this on ebay.

http://www.ebay.com/itm/Kawasaki-VN800-Vulcan-Classic-Drifter-VN1800-Fuel-Petcock-Repair-Kit-18-5023-/310587993104?pt=Motorcycles_Parts_Accessories&hash=item48507cac10&vxp=mtr

[greenbarn]

Thanks John for your input on this.  I did check the diaphragm pretty closely, and did not see any holes. I think if the diaphragm did leak it either would either 1) not open with vacuum, or 2) would leak out on the ground.  I suspect what you said about the spring is correct - that it's compressed.  I could prob'ly just stretch it out a bit and it might work,  but I thought since I have the tank off, and have disturbed all of these 12 year old seals, I might as well replace them at this point in the game.

[John Hopkins]

I added a footnote that might help..

John.

[greenbarn]

Thanks John for the input.  Actually the 800 petcock is a vacuum- controlled petcock.  There is no off position.  I've already had it all apart, inspected, re-assembled, and tested (with air as you suggested) and it still leaks (meaning allows air from "inlet" to "outlet" ) in "on" or "res", which it should NOT - these passages should only be connected when the vacuum opens the diaphragm.  Since I couldn't find anything wrong visually, I figured either the o-ring is not sealing good (maybe too hard/dry??) or more likely, the return spring is not strong enough to hold the plunger closed.

I ended up ordering an aftermarket petcock repair kit from J&P cycles.  I decided on this route instead of the factory parts b/c I had a couple other things I wanted/needed anyway - like a 16 mm plug wrench (another thread) etc.

Hopefully next week I'll have this to put it in and see if it works...

[John Hopkins]

As nobody has answered yet I will give it a go..

I have stripped and repaired several petcocks like this and they are all pretty simple..

Now it is possible that the 800 is very different to the 1500 but the 1500 is not a vacuum fuel tap..if the 800 is a vacuum fuel tap or petcock then instead of just having the one outlet hose it should have another hose at the back of the petcock which sucks air from the tap to the carb, this provides the vacuum, if that hose has slipped off you will not have a vacuum and the fuel will not flow...

So based on this I am going to go with the same petcock as the 1500 before FI.

First take a photo of the petcock attached to the tank and the hose..

Photo's before during and after doing any work pemove the probability of incorrect re-assembly..

now consider this statement as a first step..

I noticed my fuel petcock is allowing fuel to leak through it, while in the "on" or "reserve" positions.  (no actual "fuel leak" i.e. dripping on the ground, just leaking through to the carb).

Now look at the diagram and consider this..

The petcock has three positions...

ON..air or gas (petrol) can pass through the long tube to the outlet at the bottom of the petcock and into the fuel pipe but not through the short tube..

RESERVE..air or gas can pass through the short tube to the outlet but not through the long tube.

OFF..no air or gas can pass throught either tube to the outlet..

You can test the switch in each position by blowing through the long and short tubes and putting your finger over/ close to the outlet..

From this description you can see that fuel should still feed to the carb even with the engine switched off and you should switch off the petcock when parking the bike..

As a foot note, having re-read your post the centre of the diaphragm (if fitted) has a tubular section that the spring sits in, if that is damaged or deformed the fluid may leak past that section which should serve to block off the inlet from both the long and short inlets, if the spring is condensed this could prevent the tubular part from sealing..

A closer look at the centre section of the diaphragm while gently stretching it may reveal a split or pin hole and gently stretching the spring if the diaphragm is good may cure your problem.

I hope this helps.

John.

[greenbarn]

Well one thing leads to another....  When I took my tank off to do some other projects, I noticed my fuel petcock is allowing fuel to leak through it, while in the "on" or "reserve" positions.  (no actual "fuel leak" i.e. dripping on the ground, just leaking through to the carb).

My understanding is that in the on/reserve positions, the petcock should basically function as a shut off valve, and only open when the running engine supplies vacuum to the diaphragm on the back of the valve.  There is a drawing (random google pic) attached as a reference, for a valve of basically similar design.  The way I understand this gizmo is that the O-ring (670) closes off the fuel, which is pushed in place by the spring (92081) on the outside of the diaphragm.  When vacuum is applied to the diaphragm, it pulls the stop out, letting fuel go by the o-ring.

I dis-assembled my valve, and honestly can't see anything wrong with it.  Ther is no visible hole in the diaphagm, and the o-ring seems to be intact.  The way I see it, the only thing that could allow the leak when not running is the o-ring and spring?? SO, even though they look fine, I guess I need to buy some parts.

Has anybody out there had to do this repair?   What parts did you use?  The only posts I saw in the history referenced buying an entire new valve.

Choices:

1) Amazon has an aftermarket kit (made by K&L I believe), and other retailers (J&P cycles etcl) but I saw a couple of negative reviews.  You never know if this is from bad product or operator error.

2) Dealer can get individual parts, but I wasn't clear talking to the parts counter guy that I was getting everything I need.  I could have him fax me his diagram to verify.

3) aftermarket OEM non-dealer parts supplier:  there are several OEM on-line suppliers.  However, they all seem to use the same diagram and I don't see any part numbers for the diaphragm itself.

Has anybody used the K&L kit??