Still leaking = user error?

[reverbtank]

I'm in my rookie year, so I can still ask dumb questions. I just had both petcocks rebuilt, but I'm still finding small puddles of fuel on my garage floor after sitting for a few hours after riding. It's not a lot, but it's enough to get my attention. Am I using the petcock settings wrong? See pic- isn't this 'off'? '73TX. Thanks!

 

[MaxPete]

Hi Reverb:

Your fuel system actually has four (or possibly only three depending on the year and model of your bike) valves that control the flow of fuel from the tank:
- one or two petcocks on the underside of the tank (I think you have two):
- a valve inside each carburetor that controls the level of fuel in the float bowl.
The float bowl valves are NOT intended to shut off the fuel on your bike - and will almost certainly leak if you leave the petcock(s) open.

The proper way to leave a motorcycle fuel system is with the petcock(s) shut off when you are not riding - both of them and it does appear that you have the one in the photo in the off position.

Some later models have vacuum operated petcocks which are supposed to shut themselves off when the engine is not running and open up when it is started..at least that's the theory. The word around here is that these vacuum models get leaky when they get older (don't we all...) - so a lot of folks with the later bikes switch over the manual petcocks.

So - If you are shutting off both petcocks when you park the bike, then it should not leak onto your floor and if it does, then your petcocks are not working properly. The key thing is to get this issue fixed. Leaking gasoline is no joke and when you consider where you are toting 3.5 gallons of it....

 

[fredintoon]

I'm in my rookie year, so I can still ask dumb questions. I just had both petcocks rebuilt, but I'm still finding small puddles of fuel on my garage floor after sitting for a few hours after riding. It's not a lot, but it's enough to get my attention. Am I using the petcock settings wrong? See pic- isn't this 'off'? '73TX. Thanks!

Hi reverb,
nah, your petcocks are likely working OK, it's that you are mis-reading them.
Petcock lever pointing down is ON, pointing forward is STOP and pointing back as shown in your photo is RES.
At least the TX650 has an actual STOP position that'll turn the gas off if you switch it correctly,
rather than the later models vacuum-operated auto-off system what don't always work right.
EDIT I just checked the manual petcocks on the later model Standard tank I have on my Heritage Special.
The petcocks on my tank are different to yours, mine ARE turned OFF when the lever is pointed back as in your photo.

 

[MaxPete]

+1 - and there are no dumb questions Reverb.

 

[wrenchjohns]

Pull the fuel line off and see if the petcock is leaking. Toilet tissue is a great tester, the smallest leak can be detected. My petcock leak was the o-ring between tank and petcock, showed up on the screw heads. john

 

[MaxPete]

+1 - and if you really have trouble getting it to stop, I'd recommend Hylomar Blue (look it up on-line). Hylomar was invented by Rolls-Royce for aero engine work and it seals up fuel leaks and remains flexible. Amazing stuff really. A tube is in the $20-25 range - but you don't need much and so it will last a loooonnngggg time.

Just be careful not to blob is around too much - you don't want it to travel down your fuel line and get into a carburettor. THAT would gum up the works really well.

 

[reverbtank]

Thanks, all. It takes a Village.

UPDATE: The 2 leaks are not coming from the carbs, but are coming from the thicker tubes that dump near the high stand. See pic. Is that petcock related?

 

[MaxPete]

Those two tubes are overflows from the carburetor float bowls. Their role is to take any overflow from the float bowls and dump it so that the fuel winds up under the bike - unfortunately just ahead of the rear tire - but at least not all over the hot exhaust system. So, it does appear that your float bowl valves (or at least one of them) are leaking - but that is not a surprise because they are not intended to seal tightly. It also means that your petcocks, while they may not leak externally, are not shutting off and are still allowing fuel to flow out of the tank and down to the float bowls.

This is still not good - because you have a potential fire hazard, fuel is not good for your tire and you are wasting fuel and likely stinking up your garage which will get you into trouble with Senior Management..

Finally, a bit of terminology: those overflow tubes are near your centerstand (so-named because it is mounted on the centreline of the bike) and the other stand is called the sidestand - because it is mounted on the side of the frame and allows the bike to tilt toward its left side.

Cheers,

Pete

 

[reverbtank]

Thanks again, Pete. Getting smarter everyday because of the 650 family.

I'm going to order a couple of new petcocks from Mikes and be done with it.

Questions on that procedure to come!

 

[MaxPete]

Reverb: do yourself a favour and order a bunch of those fibre washers too and I'd also suggest a set of new screws. I tried to re-use a fibre washer and it leaked - badly but new ones always seem to be OK.

Finally, (and it isn't much more money - like maybe $20-30) - go on the web and get yourself a set of Vessel JIS screwdrivers. They're bright blue-green in colour and are always on sale on Amazon.

All of those screws on your bike that look like Phillips - are NOT Phillips. They are Japanese Industrial Standard and a Phillips screwdriver is more likely to strip the head than loosen a tight screw. Alternatively, you could slip down to the hardware store and get some metric socket head capscrews (i.e. Allen screws) - they won't strip.

 

[fredintoon]

Thanks again, Pete. Getting smarter everyday because of the 650 family.
I'm going to order a couple of new petcocks from Mikes and be done with it.
Questions on that procedure to come!

Hi reverb,
before you go through the hassle of switching your existing petcocks read post #3 again and try turning your petcocks from "reserve" to "off"

 

[MaxPete]

Fred - you're the best! I missed that completely.

 

[TwoManyXS1Bs]

The petcock in post #1 pic is in the "stop" position.
You read the top part of the petcock lever as though it was a pointer.

This might help:

http://www.xs650.com/threads/carbs-and-petcock-leak.31093/#post-313462

 

[Bob Kelly III]

Yep Fred Caught it ! points fer Fred ! LOL I was reading this thred just now and it hit me that his bike was on PRI on my later modled machine ....
I don't have much experience on earlier machines but know that they alwayse had a reserve in the 1970's....
so he wasn't turning the gas off he was turning it to reserve...which leaves the gas on ....
it still shouldn't leak though in my opinion and I would sujest re setting the floats as per the technical section under carburation on this forum.
.....that pic of the underside was a good indicator eh Pete ?
..... i don't think I have those tubes on my bike ..... LOL
2M ! OH no it's a Pointer type ! well that figures ...then Fred and I are dummies and missed it ! LOL

Bob.........

 

[peanut]

I still think there seems to be some confusion about the position of the tank petcock in Reverbtank's image

If you look at the cam below the lever it is perfectly clear that the petcock is set in the stop or closed position.

The petcock lever is set hard against its cam stop (fully anti-clockwise) so therefore the petcock lever MUST be set at the stop or closed position in the image.

The float needle valves are letting by which is going to make idling a nightmare . The carbs will need removing for cleaning and resetting the float levels so new float needle valve and jets might be a good idea.

 

[Bob Kelly III]

Well for some reason , all the bike makers through the years used 2 methods on their Petcock levers they had a Pointer on them at the first 60's and 70's and the lever itself was oppisit the indicator so later on they changed it and now the lever itself is the indicator.... as in my 83' XS650
when the lever is all the way back it is on PRI or full flow without the diaphram working.... and all the way forward if OFF no fuel at all....
earlier versions of bikes went through several diferent versions of lever positions very early hondas had the reserve all the way back , straight down was on and forward was off.... Most were like this but not all... some didm't have a reserve at all, just an on and off position
the beastie in question looks to have the lever forward for OFF , down for Run and back for Reserve..... but I may well have that Reversed and it be all the way forward is reserve, down is ON and all the way back is OFF..... if 2M says it's off in that position then I'ed believe him !
at any rate get your glasses on and look at the lever's housing it should have it marked on there what position is what ! Mine was extreamily hard to read...so I guessed at it and found I guessed wrong ! after cleaning and careful scrutiney I finally desifered the stamps as being off (forward)on(down)and PRI (as back) the PRI stumped me..... but sense it has a "safty feiture" of the vacuum diaphram in the petcock it became appairant why the PRI position to PRIME it for starting ( sense it by passes the other settings and allows gas to freely flow)
.....
I know.... more info. than ya needed but it's interesting nontheless ! LOL
.....
Thanks 2M ! your adding that picture helped allot ! <GRIN> it is indeed a Pointer type petcock . not one many of us are used to any more ! HAHAHAH !

....
Bob..........

 

[peanut]

the beastie in question looks to have the lever forward for OFF , down for Run and back for Reserve..... but I may well have that Reversed

....
Bob..........

To determine the petcock lever position on any petcock you just need to look at the lever cam stops as I pointed out in my previous post.

Once it is understood how the lever rotation is stopped at each end of its travel by looking at the cam and lever rotation stops then it is immediately obvious how any particular petcock works and one never needs to rely on others to say if it is on or off .

 

[Bob Kelly III]

I agree Peanut !.... Now ! LOL thank you and yes I think he's going to have to pull the carbs off and at the very least adjust the floats to specks
i would clean all the passage ways while you have the carbs off though get a can of sprey carb cleaner and take everything off the carb that will come off.... and clean it well..... it's not a fast job (at least for me ) compressed air to blow out those passageways is good as well.
but if your looking to just get by for a while a simple float adjustment may well take care of it .
the float level in these XS650's is extreamily HIGH compaired to other bikes I guess it's because of the CV carbs and the super tiny idle passageways
get a good MM Ruler and take your time and adjust the float level perfectly and you should cure the problem
these have the touchiest floats level settings I have ever incountered ! it's not a Holly or stormburg carb where being close is good enough these things have to be perfect ! I fought mine for weeks ( i'm embarrased to admit) but I did.... so learn from my mistakes !
Bob......

 

[Bob Kelly III]

Peanut....
I just went out to my bike and checked it ..... it has res as the forward position, on is down and PRI for the back.....
there is no pointer on this petcock ! they go by the lever on this thing ( I know I checked with the fuel line off)
what is marked as RES.... is not RESERVE it's OFF...... ( or maybe I was out of gas when I checked it ? LOL) anyway I am so certain that is the OFF position it is where I put it when I'm done riding it . and no fuel leaks have been found...
they (the manifacturers) have played so much with the petcocks over the years that to me, each bike is diferent and ya gott'a look and figure out how to turn the gas ON just to start it for the first time !
I bet I'ed have a hell of a time with a brand new bike ! LOL
My 1100cc Honda shadow had a weird petcock on it.... I can't recall right now what it was but it was diferent than all the rest, that much I do remember
HHAHHAHA !
.....cheers !
Bob.......

 

[reverbtank]

Thanks for the POVs. I'm pretty sure I'm using the lever correctly seeing that the short end, the pointer end, can only point up (ON), so when I point it left (STOP), it should be off. I'm going to order 2 new ones and try to set them myself.

@MaxPete- thanks for the tip on the Vessels. Can you point me to a Mikes link for the proper fibre washers and screws you recommend? I'm ordering https://www.mikesxs.net/yamaha-xs650-petcock-non-vacuum-type-oem-447-24500-02-00.html