gas leak

[Batkinson]

Got about twenty miles out from congested traffic and hit my first stop, smelled gas and looked down to see drop vaporizing on engine block and pipes.......small puff of smoke, large gas smell. 

took some time to  cool things off and then reacquired a strong belief in positive thinking as I chanted "don't burn baby" through long ride back home with many stops.

Removed the fairing ( thanks Frakenduck  http://www.motobrick.com/index.php/topic,406.msg725.html#msg725) and can see fluid trail from under gas tank down to block and pipes. ( see pics, fluid on third body) Next step is tank removal and checking the stuff mentioned here ( http://www.motobrick.com/index.php/topic,535.msg1304.html#msg1304) but am thinking best to just replace all the hoses and seal involved.

Also noticed a lot of oil residue on left lower fairing, left crash bar, and block. I have put about 1000 mile son it in six months of near daily riding...is this normal. I was told by previous multi bike multi year rider not to worry that oil fluid does not reach multi tool as long as glass indicator shows good. Gonna do all the maintenance i can soon as the weather cooperates but would like to hear on the oil question.

[Laitch]

Also noticed a lot of oil residue on left lower fairing, left crash bar, and block. I have put about 1000 mile son it in six months of near daily riding...is this normal. I was told by previous multi bike multi year rider not to worry that oil fluid does not reach multi tool as long as glass indicator shows good.

What's the multi-tool?

The stock shock adjuster has a line scribed on its handle for measuring the transmission oil. It isn't used for checking the engine oil level. That is the purpose of the sight glass. Was the multi-bike rider riding the bikes all at the same time? :giggles

Oil can come from the crankcase vent, the camshaft cover and a vestigial vent tube that some bikes have at the front of the case that can be plugged, to name a few places. Your bike shouldn't leak oil. Clean the case to see if you can identify the area next time it leaks.

[Martin]

Clean the engine then spray the suspect area with spray on talc this will help show the leak.
Regards Martin.

[kennybobby]

check around the seam on the bottom left side of the fuel tank for bulging paint bubbles filled with fuel from pin-hole leaks

[Laitch]

check around the seam on the bottom left side of the fuel tank for bulging paint bubbles filled with fuel from pin-hole leaks

+1

[Batkinson]

thanks for the help, will check the gas tank in the next couple of days.

removed the tank, air cleaner housing and associated hoses. still see lots of fluid on the third throttle body so plan on removing throttle housing assy with plenum attached as soon as I am comfortable with process and pics.

did notice lots of oil on the engine under the air cleaner housing and found an unknown piece of metal laying there as well as the protection cap i noticed was missing.

pics attached - am not certain if these will help, or if it's better to continue cleaning everything up before adding more pics:

[kennybobby]

The spooge on top of the motor is typical of an old k-bike that has never had the housing removed to clean under it--not a problem, clean it if it bothers you.

What do your fuel regulator hoses look like--any cracks in the rubber there?

What's that hose cable-tied to a bracket in the pictures--that looks like someone's been fixin something.

If you are smelling fuel, then that is considered an urgent sort of thing to find the source--oil is one thing, but gas is not very forgiving...

[Batkinson]

Thanks again for the feedback, sorry for the delay but both PCs at the house have crashed. Well, one crashed with a bad pool header and the other had a glass of red wine dumped in it.... anyway, hoses are all new and in good shape. Looked at the fuel tank and see the following.


Is this indicative of a fuel leak ?  There has been no leak from the tank while sitting on a towel on the shelf.

[The Mighty Gryphon]

Based on what I think I see, my money is on the seal where that electrical connector comes through the tank.

[Batkinson]

I am with you on the seal where that connector for fuel pump power and fuel level indicators comes through. Unfortunately I am having some difficulty in finding any parts diagrams which refer to the connector assy or associated O-rings/gaskets, or a remove/install procedure. Any assistance would be greatly appreciated.


Also, I think I should go ahead and replace the fuel cap gaskets since this doesn't look good to me....

[Martin]

+1 replace the seals and "O" rings. If they allow water into the tank the water mixed with ethanol form an acid. This  will corrode the tank and you will definitely get leaks.
Regards Martin.

[Laitch]

I am with you on the seal where that connector for fuel pump power and fuel level indicators comes through. Unfortunately I am having some difficulty in finding any parts diagrams which refer to the connector assy or associated O-rings/gaskets, or a remove/install procedure. Any assistance would be greatly appreciated

Where have you looked, Batkinson?
Get the K75/K100 BMW repair manual from the Technical Library Index here. The manual is stored under the heading BMW Workshop Manuals. Look in it for the Fuel Tank Layout diagram. It's just a nut-bolts-and wires procedure but patience and penetrant can be useful. Check the MAXBMW parts fiche for component part numbers.

[Batkinson]

uhhhh yeah, thanks.


I checked the manual for a good amount of time by both manually scrolling and using cntrl-f to search. I have looked at page 16-06.0


I found lots of references to fuel pump and a procedure on page -16-15.0 referencing the removal and replacement of the actual fuel level sensor,  but the electrical connection, the big black circular plug as shown in my pic, I can't find referenced or am not making the right connection between the drawing and the reality.


I had checked the microfiche at Bob's BMW and the MAX BMW fiche ( sections 16_0238,  16_0808, 16_0809, and 16_0815) but can't visualize any of those parts as the connector. When I look down into the tank the fuel pump assy seems displaced too far from where the connection passes through, and it doesn't seem  the connector is a part of the fuel pump. Perhaps brainlock from too much gas fumes?


I'll take another look, but I hate just wrenching on the nut without a better idea of WTF I am possibly screwing up. Any help is greatly appreciated

[Laitch]

uhhhh yeah, thanks.

uhhhh, if you can't figure it out from the drawing on 6.0, I'll go for a walk. It's a beautiful day.

[Batkinson]

uhhhh yeah, thanks again.


First  response from one of the people who is arguably among the most knowledgeable members here is to RTFM, but you don't know that I exhausted every source I could before asking for help and perhaps that is your stock reply to Noobs. Every manual, every pdf, all the threads related to fuel leaks, fuel systems, fuel pumps, fuel level, fuel lines, air lines, wiring, connectors, and I could find no answer.


Then you apparently got butt hurt because my frustration came though in my reply, though I did politely respond in detail to your question of  where I had looked. I still have difficulty in finding any reference to the electrical plug or its associated sub parts like O-rings or gaskets, and to my eyes there is no new info on 13-6.0 or any of the parts fiches. I repeat my request for info anyone might have.


 Please enjoy your walk. I suggest an uphill route so the pressure might return your head to light and air, and then you might want to share more helpful information to a beginning learner.

[Martin]

Different fuel sender units for the K100 - hrsbstaff.ednet.ns.ca
Might help. :dunno Doesn't seem to be much info on early types.
Regards Martin.

[Laitch]

I'm back! 

[Laitch]

It took me two seconds to find this using Google with the words K100 early fuel sender connection. I would have found it sooner but I spent a few moments laughing at your response, Bat. It's also in the MAX parts fiche.

Early sender unit with big black plug, from MAX BMW parts fiche.png (62.34 kB . 500x323 - viewed 622 times)

[Batkinson]

Thank you Martin and  Laitch. I did not know this was an early model sender, but appreciate the great help and info.

[The Mighty Gryphon]

In defense of Batkinson, let me say that I looked at that parts fiche several times and didn't see parts 5 and 6 as the parts in question.  Like the O.P., not ever having that particular sending unit apart I didn't know what the parts would look like on the fiche.  That it was listed as a gauge and not a sending unit didn't help either.

It sounds like Laitch is getting a bit cranky from cabin fever being snowed in up in the Green Mountains.  I hope spring comes early for him so he can get back out there chasing the kids off not only his own, but the neighbors' lawns as well.

[Laitch]

I hope spring comes early for him so he can get back out there chasing the kids off not only his lawn, but the neighbors as well.

I let the bears do that.

[White Dog]

I, too, have experienced a gas leak.  Gas was dripping from the middle sides of the tank--off the heat shield material.  Took me way too much time to drain the tank in order to take it off.  Once off, I still didn't find the leak until I took the mechanic's advice at BMW to add fuel while the tank was sitting on my work bench.  Sure enough, gas began dripping but since I had removed the heat shield, I could now see that the leak was coming from my sending unit located at rear of tank (model K75).  I purchased a new O ring at BMW and pulled the sending unit.  The old O ring was mashed flat where obviously the mounting plate had been tightened down too much.  The bolts were difficult to unloosen.  So, I believe that takes care of my leak.  I'll torque those bolts to factory specs, but first I want to find the postings on how to adjust the sender unit itself, as my light comes on at 130 miles and I can easily run 160 miles and have about a gallon of fuel left.