help diagnosing gas leak from pod filter

[mrhammer2u]

Hi all. When I know I'm only going to be parked for an hour or so,...I don;t turn off the petcock. Every now and again the left (when sitting on the bike) pod filter will be wet with gas. Is this is a leak from the carb? I understand if I left petcock on over night,....but not for an hour or less.

12k original miles, XS1100SF, UNI pod filters.

Thanks!!

[tcoop]

I have the same problem. Your float is sticking open and if you still have the octy it is not closing when the bike is shut off.

I just replace the diaphragm in the octy on mine and that helped but I still need to service the carbs to fix the problem.

[mack]

leak

If it smells like gas, it's the carbs leaking. If you can determine which pod is wet then you'll know which carb is leaking.
Good and bad news here. If the leak is intermittent, then it's most likely a hanging float on the bowl gasket. If you take a screw driver and tap the bowl with the handle, it may release the float and allow the float and needle to seal.
Bad news is the long term fix is to remove the carbs, then the bowls and trim all the gaskets back so the floats cannot hang in the future
You should at this point, check your crank case for the smell of gas in the oil. Carbs are tipped toward the cyclinder head and gas leaks can drain into the cyliders and get passed the rings into the crank case. Big end and crank main shells don't play well together well with gas. If you have any smell of gas, drain the oil and put in new stuff before you start the motor again!
The real bad news is that, while you only noticed the gas in your pods when the motor was in a tail down position, it may not have been intermitnet, and may have been leaking into your crankcase for some time now. Smell your oil soonest and don't be smoking while your doing it! More than one of our members have burnt down a shed and lost a bike in this way!

[mrhammer2u]

Thanks guys. Are we talking total carb rebuild or just replacing a single O-ring? I'm re-jetting in about a month and would like to have the proper parts on hand.

Octy = ? If you are referring to the stock SF fuel system with dual petcocks,..yes, I have that.

[TopCatGr58]

Hey Hammer,

The Octy is the vac. controlled fuel valve that goes between the petcocks and the carbs....it has 4 hoses from the petcocks going into it, and 2 going to the carbs coming out of it, along with 1 vac. line to the intake boot, so it's 1 short of a true Octopus count of 8 lines, but close enough!

IT has a diaphragm inside of it that controls the fuel flow, with a little piston/spring on one side that often corrodes and rusts and gets stuck which can prevent it from working.

T.C.

[donebysunday]

The 0-ring sealing the petcocks to the tank and the lines are the first place I'd look. It is common for the washer in the petcock (I call it a wizzer valve cause it dries out and allows pissing fuel all over your engine) to get hard and crack. Put the petcocks in the OFF position and see if it still leaks, let it sit over night, this will tell you that the washer it the petcock is bad. Yami gets $12 ea. you can get them from online sources for under ten but then add some other things you need to share S&H. Just use your fingers and follow from the bottom of the bowls up to the octi and then to the petcocks to see where the leak stops, then you'll know where to look for it.

[mack]

Octy

Octy or not, fuel is getting passed the needle(s). Either it's a hanging float,dirty fuel valve seats or the tips of his needles are dirty or damaged.

[mrhammer2u]

Thanks all. One last question......should I rebuild the carbs by just getting the o-rings/gaskets with a kit like this....
http://www.ebay.com/itm/390954370048...%3AMEBIDX%3AIT

OR

go all out with a kit like this?
http://www.ebay.com/itm/390840800391...%3AMEBIDX%3AIT

I only have about 13k original miles on the bike and don;t want to spend more than I have to. Wondering if the whole kit n kaboodle will be overkill.

[donebysunday]

With that low mi. machine I can't see how jets and needles can be worn, dirty yes, possibly corroded and then you would need replace them with the bigger kit.

Find out if those jets and needles are the real mikuni or not ?

You can go to the model builders shop and buy drill bits that you can then check the jets with the dull end what the orifice size really is. I think it's 75,76,77 for the pilots and 55,56,57 for the mains. Take one ea. of your jets (pilot,main) to the store and match up, then buy a small assortment of bits, tape them to a paper or card board at the store and number them. Now you can check what size jets your putting into your carbs !

Draining the float bowls into a clean cup will tell you a lot about whether you have dirt in the carbs, if so all you need is a good cleaning.
I made screwdrivers to fit the jets, then found a few that were really stuck and ground bits to fit the jets for my impact driver, have not lost a jet since due to breaking the heads off. Use some PB blaster and heat or carb cleaner to liquify the blaster, either gets it to seep down into the treads or wait till the carb cleaner evaporates and use the heat too.

[mack]

cleaning

I wouldn't rush out and buy anything yet. Pull the carbs and follow the tech tip on cleaning them. If they are the original SF carbs, you probably have non viton tipped needles and the associated seats. These can be easily cleaned and reused for years. Viton tipped needles deteriorate fairly quickly because of the ethanol. If the bike was running well for the PO then rejetting shouldn't be required. In any even, if you do buy rebuild kits, buy mikuni only, stay away from "K&L", they're poor quality junk.
When you get the bowls off, have a close look at the float from the carb that was leaking. Shake it and listen for fluid sloshing around. It may have a pin hole in it and that will cause it to sink and prevent the needle from seating and shutting off the fuel. careful with them as they will be brass. If they are not brass then someone has been inside the carbs before you and exchanged the brass with plastic floats so the leak is at the needle/ seat or possibly the float was hanging up on the gasket.
I didn't notice what exhaust you have. But if the carbs have been rejetted to account for pods, then the standard kits will be useless anyway. You have to buy the required jets separately.

[mrhammer2u]

I wouldn't rush out and buy anything yet.

The problem is, my local MC shops don't carry too much, if any stock for these old bikes. Wanted to have the parts on hand. Thanks for the advice on the K&L. Will look for Mikuni.

[cajun31]

Hey hammer

the first link you posted wouldn't be a bad purchase, however what Mack is trying to say is don't invest in new jets just yet. Most everything inside the carbs can be cleaned and reused. The float needles are of the kind that don't go bad and if removed and cleaned of gunk and debris work fine, unless for some reason the are beyond cleanup/repair. Usually not the case but there are exceptions. The reference to mikuni parts is for the jets themselves. If you run across one or one is destroyed in the removal process it should be replaced by the same size original mikuni jet which can still be purchased from Jets are us. Replacing the o rings and float gaskets wouldn't hurt anything but is sometimes unnecessary depending on the existing condition of the old ones. You are going to have to remove the floats and inspect the float needle assembly period. That is more then likely the source of the flooding. As was mentioned by mack, if this has been going on for a while you will definitely smell gas in the oil. Very dangerous situation and should be dealt with immediately. I know what you are saying about having parts on hand, however as quickly as parts can now be acquired with the internet I would take things one step at a time and only buy what you need as you proceed. Good luck and keep posting with your findings and progress.