Author Topic: WANTED: Flapper for K75 / K100 gas cap (Read 6734 times)

rbm · « **on:** August 15, 2018, 01:39:33 PM »

UPDATE: I received a flapper in the mail this week from a kind donor over on the other forum. I'm not searching any more for one. Thanks to all who offered to help me.

BMW calls this part I'm after an Intermediate Plate (part number 16112309404). Lots of guys remove this flap from their gas caps, but I want to install one on my K75. Does anyone have one lying around that could be donated?

Looks like this (picture from the Intrawebs):

johnny · « **Reply #1 on:** August 15, 2018, 05:58:02 PM »

i gotts several on a chain i wear at bohemian grove...

Chaos · « **Reply #2 on:** August 15, 2018, 06:03:23 PM »

I'm saving mine so I can revert the bike back to bone stock when it becomes priceless collector's motorcycle :hehehe :hehehe

Motorhobo · « **Reply #3 on:** August 16, 2018, 06:32:27 AM »

I think might have an extra. Let me take a look and I'll get back to you tomorrow.

Scott_ · « **Reply #4 on:** August 16, 2018, 06:38:04 AM »

I'm thinking I might have 1 or 2 in a box yet also. I can get a look later today after work.

Motorhobo · « **Reply #5 on:** August 18, 2018, 01:04:39 PM »

I had an extra but I've looked everywhere it could possibly be and it's not in any of those places. I'm sure it will turn up when I need it least, but bottom line is sorry Robert, can't find the damned thing! Maybe you'll have better luck with Scott's superior organizational skills...

If it does turn up I'll let you know.

Chaos · « **Reply #6 on:** August 18, 2018, 01:12:27 PM »

Did you find one yet? I'll donate mine since the bike's never going to get restored and I should reduce clutter.

rbm · « **Reply #7 on:** August 18, 2018, 05:30:40 PM »

Thanks all for the effort in locating one of these intermediate plates. Caveman on K100-forum has packaged one up for me and sent it off. I don't need multiples so I will not be requiring one from you Johnny, Chaos or Scott. Cheers guys.

alabrew · « **Reply #8 on:** August 22, 2018, 06:35:41 PM »

Just out of curiosity rbm, why do you want install a part so many remove?

rbm · « **Reply #9 on:** August 22, 2018, 07:02:35 PM »

Quote from: alabrew on August 22, 2018, 06:35:41 PM

Just out of curiosity rbm, why do you want install a part so many remove?

~~Their purpose is to contain fuel vapours within the tank so that they vent through the proper channels and not out the gas cap. This was a California clean air requirement.~~ Se Chaos' explanation below.

I have a different purpose in mind. For some strange reason, liquid gasoline finds its way past the sealing rings on the cap and onto the paint around the lid on my tank. This deteriorates the paint badly. I repainted my tank this past winter and already the paint has started to peel off around the lid in under one riding season. I replaced all the rubber parts in the lid at the same time as painting hoping that new seals would stop the problem. They didn't. So, I will depend on the flapper to act as a check valve to prevent sloshing gasoline from migrating past the cap.

Here's a picture of the damage that has been caused by the gasoline in just the past few months.

Motorhobo · « **Reply #10 on:** August 23, 2018, 05:27:54 AM »

Quote from: rbm on August 22, 2018, 07:02:35 PM

Their purpose is to contain fuel vapours within the tank so that they vent through the proper channels and not out the gas cap. This was a California clean air requirement.

I have a different purpose in mind. For some strange reason, liquid gasoline finds its way past the sealing rings on the cap and onto the paint around the lid on my tank. This deteriorates the paint badly. I repainted my tank this past winter and already the paint has started to peel off around the lid in under one riding season. I replaced all the rubber parts in the lid at the same time as painting hoping that new seals would stop the problem. They didn't. So, I will depend on the flapper to act as a check valve to prevent sloshing gasoline from migrating past the cap.

That's why I put mine back in. If the bike is on the sidestand and the tank is full without that thing, it can weep fuel. I think the flapper might prevent that, or at least reduces the amount of fuel that will fit into the tank so one isn't tempted to overfill such that weepage occurs. I don't know if all this is really true or whether the flapper really makes any difference, but like rbm I had to repaint my tank due to weepage and I never want to have to go through that sh*t again.

Chaos · « **Reply #11 on:** August 23, 2018, 10:23:48 AM »

Flappers originally had nothing to do with sealing or vapors, they were there to prevent you from putting leaded gas into a vehicle that required unleaded. The unleaded nozzle was thinner and fit into the flapper hole, the leaded nozzle was too thick to fit. Another benefit on the K bike is it prevents topping the tank, leaving a bit of air space at the top which might allow a full tank to deform in a crash without bursting. Automobile tanks are also designed with an air space for that reason.

CNRED · « **Reply #12 on:** August 23, 2018, 12:19:11 PM »

Quote from: Chaos on August 23, 2018, 10:23:48 AM

Flappers originally had nothing to do with sealing or vapors, they were there to prevent you from putting leaded gas into a vehicle that required unleaded. The unleaded nozzle was thinner and fit into the flapper hole, the leaded nozzle was too thick to fit. Another benefit on the K bike is it prevents topping the tank, leaving a bit of air space at the top which might allow a full tank to deform in a crash without bursting. Automobile tanks are also designed with an air space for that reason.

Good to know, i removed mine when I rebuilt the gas cap because the scerws were rusted nto the point the had to be drilled out.

rbm · « **Reply #13 on:** August 23, 2018, 05:56:49 PM »

Quote from: Chaos on August 23, 2018, 10:23:48 AM

Flappers originally had nothing to do with sealing or vapors, ...

Oh, I had no idea Chaos. I heard or read the explanation I wrote. good to know.

Motorhobo · « **Reply #14 on:** August 23, 2018, 09:01:48 PM »

Quote from: Chaos on August 23, 2018, 10:23:48 AM

Flappers originally had nothing to do with sealing or vapors, they were there to prevent you from putting leaded gas into a vehicle that required unleaded. The unleaded nozzle was thinner and fit into the flapper hole, the leaded nozzle was too thick to fit. Another benefit on the K bike is it prevents topping the tank, leaving a bit of air space at the top which might allow a full tank to deform in a crash without bursting. Automobile tanks are also designed with an air space for that reason.

I'd sad to say I'm old enough to remember that thicker leaded nozzle and how annoyed everyone was when these flappers appeared that the thicker nozzle wouldn't fit into.

Scott_ · « **Reply #15 on:** August 23, 2018, 10:20:49 PM »

The filler neck restrictors started in the early/mid '70's in the states for light duty cars/trucks. Sad to say I remember when they came out also.....

Chaos · « **Reply #16 on:** August 23, 2018, 10:30:24 PM »

Quote from: Scott_ on August 23, 2018, 10:20:49 PM

Sad to say I remember when they came out also.....

I fondly remember those big gaping 2" pre-flapper filler pipes. You probably got one of these lying around too :laughing-on-ground:

rbm · « **Reply #17 on:** August 23, 2018, 11:25:27 PM »

Isn't that a funnel used for puncturing an oil can for adding oil to the sump? I see the blade for piercing the top of the can.

Mongrel · « **Reply #18 on:** August 23, 2018, 11:45:18 PM »

That's what it looks like to me! I remember those too, and I ain't *that* old.

I have the ram problem as Rob - but if the flapper isn't the issue with gas seeping up into the tank rim where the gas cap is seated, then how else do you fix the issue? Normally I'd say new seals, but I bought a brand new OEM gas cap seal kit from MotoBins about 3 years ago and it did absolutely nothing to solve the issue.

Laitch · « **Reply #19 on:** August 24, 2018, 12:23:43 AM »

Quote from: rbm on August 23, 2018, 11:25:27 PM

Isn't that a funnel used for puncturing an oil can for adding oil to the sump? I see the blade for piercing the top of the can.

No, it's a shoehorn.

Scott_ · « **Reply #20 on:** August 24, 2018, 06:56:33 AM »

Chaos, yea, I think I might still have one in the storage warehouse......

Chaos · « **Reply #21 on:** August 24, 2018, 09:23:10 AM »

Quote from: Laitch on August 24, 2018, 12:23:43 AM

No, it's a shoehorn.

No, shoehorns are completely different

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Author Topic: WANTED: Flapper for K75 / K100 gas cap (Read 6734 times)