Author Topic: Help me NOT shoot my bike... Gas cap... (Read 13199 times)

k98DOG · « **on:** July 06, 2013, 06:31:22 PM »

I have an 86 k100 I bought a few months ago. When she's running; she runs really good. When she's not running, argggh!

Anyway we had some problems with her a few months ago so I took her to the local BMW bike shop. Let's just say that wasn't cheap. After 5 or 6 weeks I got it back. They said the fuel pump was bad AND that the fuel was contaminated. They took a considerable amount of $$$ off my bill since they had the bike wayyyy too long (that was decent of them I thought). So my bike was up & running awesome.

For a few days.

Then she quit on me in the driveway and would not start again. She was getting fuel and air. She had spark. I assumed the fuel pump was bad again so I got a friend with a trailer (they are worth their weight in gold) to help me out again. A few doors later the local BMW place called and said the bike was ready and that she had contaminated fuel again (no charge for this). So I picked her up and she ran great.

I drove her to Pensacola (FL) earlier this week and she ran flawlessly. It rained every inch of the way on the way back. I was cruising 80ish most of the way there on I85 & I65 (more like 35-55 on the way back - because of the rain).

So this morning she cranked but was sounding like she was skipping? As I had driven almost 150 miles w/o fueling up I thought I'd go refuel while I had the chance. So I filled up at the gas station about 2 miles away w/real gas (93 Octane). When I opened the fuel cap I noticed water(?) on the inside of the cap. And I noticed that the gasket appeared to be worn. I couldn't get her to start for about 10 minutes and then she was sputtering. So I went to the nearest auto parts store and bought a can of Sea-Foam and put her in the tank. I took her for about an hour ride around town as her sputtering got less and less.

So now I'm convinced that I'm not buying bad gas, and that the several trips to the local place have done nothing but piss my money away.

Here's the picture. Tell me if I'm wrong...but I think the gasket is not making a seal and that when it rains water is getting into my fuel system.

Thoughts?

TimTyler · « **Reply #1 on:** July 06, 2013, 06:46:17 PM »

Here's what my cap looks like.

I'd say you have a very worn or missing gasket?

K75RT Keith · « **Reply #2 on:** July 06, 2013, 07:14:30 PM »

Yep, looks like the gasket is shot. If you find someone who has the gasket, please post their info. as BMW doesn't carry them as a separate item anymore. Also check your drain hole on the side of the filler. Might want to run a wire thru the drain to teh hose and check the drain hose is clear of obstruction.

TimTyler · « **Reply #3 on:** July 06, 2013, 07:24:03 PM »

It probably would not be difficult to fabricate a gasket yourself if you found the proper thickness of rubber. It's just a circle / ring.

Grim · « **Reply #4 on:** July 06, 2013, 07:42:45 PM »

Gasket 10 is the main one to keep water out and is out right missing and 7 is damaged.

Is your drain plugged? When you open your cap on the left (as sitting on bike) is a slot and you will see a hole (if cap is installed correctly hinge toward seat). That hole connects to a pipe on the bottom side of the tank. That is connected to a hose that runs down the frame and will dump any water around the cap near the right foot peg. That hose is easily pinched when installing the foot peg plate or kinked under the tank.

Video on how to rebuild a cap.

Parental warning. Chris has great repair vids but mature audiences only. ;)

k98DOG · « **Reply #5 on:** July 06, 2013, 10:22:46 PM »

Awesome. As I watched the video I started feeling better about the brick in my front yard. Thanks for posting pix and for the parts schematic for the fuel tank. Also big thanks for posting the video as well.

Bier is on me if you guys ever make it to Greer SC.

Scott_ · « **Reply #6 on:** July 06, 2013, 10:25:09 PM »

I see that Tim is missing the #10 gasket too in his pic.

TimTyler · « **Reply #7 on:** July 06, 2013, 10:52:42 PM »

Nah. It's there.

Scott_ · « **Reply #8 on:** July 06, 2013, 10:57:11 PM »

Quote from: TimTyler on July 06, 2013, 10:52:42 PM

Nah. It's there.

Yep, you're right. I need to put my glasses on next time....... :yow

cy7878 · « **Reply #9 on:** July 07, 2013, 01:56:35 PM »

what about keeping the bike/tank covered? Sounds like when you park or ride, place a piece of saran rap over the tank cover can probably keep the water out.

k98DOG · « **Reply #10 on:** July 07, 2013, 07:14:45 PM »

Oddddly enough all my friends have been raggin' me because:

* I can't park my motorcycle in the garage because my wife's cats live in there.
* I'm too cheap to buy a tarp/motorcycle cover.

I broke down and bought a cover. But for whatever reason I don't use it like I should.

NOTE: When I use it I don't have problems. But I don't want to HAVE to use it. What I want is to fix the problem!

Response to earlier post about a 'weep hole' in the gas tank. Yes my ride has a little weep hole for water/whatever to drain off.

Mongrel · « **Reply #11 on:** July 10, 2013, 10:39:41 PM »

I really ought to be doing a full gas cap change, as my gasket 10 is half-melted due to summer heat and my gasket 7 is possibly getting stiff (Can't tell, but it slops a bit of fuel when leaning left if the tank is full).

Are there any alternatives for buying that complete gasket kit besides the suggestion of Bobs in the video? The US sellers always want to charge me like $30 shipping, even on small gaskets and things that would fit in an envelope.

k98DOG · « **Reply #12 on:** July 22, 2013, 05:47:51 PM »

Quote

Mongrel

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I really ought to be doing a full gas cap change, as my gasket 10 is half-melted due to summer heat and my gasket 7 is possibly getting stiff (Can't tell, but it slops a bit of fuel when leaning left if the tank is full).

Are there any alternatives for buying that complete gasket kit besides the suggestion of Bobs in the video? The US sellers always want to charge me like $30 shipping, even on small gaskets and things that would fit in an envelope.

Well I broke down and ordered 2 kits - one for me, and one for you Mongrel. The guy on the phone said that they were out of the gas cap kits but they would be making more in a couple of days. I think he said something like $26 plus shipping to my door. I have a Fedex account and I'll be glad to send you the kit for my cost plus whatever the shipping is to you. Or I will take to the post office the next time I go there. You will have to pay whatever import tariffs or taxes that there are...

If for whatever reason you don't want the kit just say so. You are not obligated in any way, shape, or form. I am sure that if you don't want it someone else will take it?

racinrich · « **Reply #13 on:** July 23, 2013, 11:21:09 PM »

heres a thought skin the cat and use his hide as a gas cap cover !!!, you get the garage back.two problems solved . :hehehe :hehehe

rcgreg · « **Reply #14 on:** July 26, 2013, 02:22:01 PM »

Bad advice, the new cat (if your wife doesn't divorce you) will use your tires for scratching posts, and if she does divorce you - you'll loose your bike !!! :)

k98DOG · « **Reply #15 on:** July 28, 2013, 05:14:34 PM »

Quote

I really ought to be doing a full gas cap change, as my gasket 10 is half-melted due to summer heat and my gasket 7 is possibly getting stiff (Can't tell, but it slops a bit of fuel when leaning left if the tank is full).

Are there any alternatives for buying that complete gasket kit besides the suggestion of Bobs in the video? The US sellers always want to charge me like $30 shipping, even on small gaskets and things that would fit in an envelope.

If you want the kit I'll ship it to you at my cost. Drop me a line...if I don't here from you by next Friday (Aug 2nd) I'll put it up for sale here..

k98DOG · « **Reply #16 on:** July 28, 2013, 07:31:43 PM »

Edited: It took me longer to watch the video than installation should have taken. If you're going to swap out parts for the gas cap then go ahead and replace this gasket (part #8 from the exploded parts diagram) while yer there.

Can someone please post the part diagram showing what they are called???

Also what is the part number OR size of the gas cap screws? The head on one of the screws was buggered up so I figure I'll replace them all while I'm there..

k98DOG · « **Reply #17 on:** July 28, 2013, 07:39:26 PM »

Hard to believe I had the fuel pump replaced at the local BMW place a couple of months ago and all the parts look like this.

k98DOG · « **Reply #18 on:** July 28, 2013, 07:40:11 PM »

And this...

k98DOG · « **Reply #19 on:** July 28, 2013, 07:41:23 PM »

It seems to me that they should have replaced the worn out gaskets and cleaned up a little better???

k98DOG · « **Reply #20 on:** July 28, 2013, 07:44:50 PM »

Incidentally the previous 2 pix were taken to show the debris that was laying between the gas tank and the worn out rubber gasket. 100% entirely preventable.

SOOOoooo in this picture what do we have? In Bob's video NONE of the smaller parts are in the black cap. When I took my black cap off to lubricate the mechanism....the little parts, gasket, and spring shot out.

HELP?

News:

Author Topic: Help me NOT shoot my bike... Gas cap... (Read 13199 times)