K75 “National Version California”?

Per the VIN, a nearby K75 for sale has the following option:

“Y749A National Version California”

Any insight into what this means? Does this make it a California emissions model? Or???

It’s a ‘94, in case that matters.

vark said:

Per the VIN, a nearby K75 for sale has the following option:

“Y749A National Version California”

Any insight into what this means? Does this make it a California emissions model? Or???

It’s a ‘94, in case that matters.

Click to expand...

That should be a "50 state" model that meets California emissions standards. In some prior years BMW did have 49 state models that did not meet California standards but got tired of it so made them all California compliant.

PGlaves said:

That should be a "50 state" model that meets California emissions standards. In some prior years BMW did have 49 state models that did not meet California standards but got tired of it so made them all California compliant.

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Okay, that makes sense. Thanks very much.

But one follow up question is why bmw would list this under “optional equipment”?

vark said:

Okay, that makes sense. Thanks very much.

But one follow up question is why bmw would list this under “optional equipment”?

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I am not sure of the years but in some years dealers ordering a California bike needed to specify that, probably as an option, since the majority were "49 state" bikes.

I did a Google search on that phrase and came up with several hits that all seemed to relate to the fuel tank. I am pretty sure it has to do with the way the fuel tank was vented to the crankcase rather than to the atmosphere.

That particular feature was a design disaster in that raw fuel could be vented into the crankcase, dilluting the oil. Later models began using charcoal cannisters to absorb fuel vapors ad re-deliver them to the induction system on a running engine. Most informed dealerships other than in California rerouted the vent hose at the first dealer service.

Hmmmm. That’s interesting.

Where would I look to see if that vent was re-routed? Would it be obvious or tricky to see without disassembly?

PGlaves said:

I am not sure of the years but in some years dealers ordering a California bike needed to specify that, probably as an option, since the majority were "49 state" bikes.

I did a Google search on that phrase and came up with several hits that all seemed to relate to the fuel tank. I am pretty sure it has to do with the way the fuel tank was vented to the crankcase rather than to the atmosphere.

That particular feature was a design disaster in that raw fuel could be vented into the crankcase, dilluting the oil. Later models began using charcoal cannisters to absorb fuel vapors ad re-deliver them to the induction system on a running engine. Most informed dealerships other than in California rerouted the vent hose at the first dealer service.

Click to expand...

They also added a little spring loaded flapper door at the opening. Not a big deal on a car, but a PIA on a bike. I don't know if all states have those accordion things on the pump nozzles that have to be held back as well, while trying to fill the tank. On my k75 I deleted the valve and capped it off at the crankcase, now the tank just vents to the atmosphere. Maybe sometime I might try to get rid of the flapper door as well.

vark said:

Okay, that makes sense. Thanks very much.

But one follow up question is why bmw would list this under “optional equipment”?

Click to expand...

Because Non-US models did not require it. It probably made the build sheet clearer.

vark said:

Hmmmm. That’s interesting.

Where would I look to see if that vent was re-routed? Would it be obvious or tricky to see without disassembly?

Click to expand...

The routing had the vent hose go from the stub-pipe on the bottom of the tank, forward and downward to a check valve and then into a stub-pipe on top of the forward, right top of the engine. The fix was to reroute the vent hose down to the right footpeg area, with the stub-pipe at the engine then closed with a rubber cap.

The "drain" hose from the filler cap area was routed to the right footpeg area. Later BMW installed a small square funnel under both stub-pipes which is called an "air accumulator" in its English translation. Then a single hose runs to the right foot peg plate.

vark said:

Hmmmm. That’s interesting.

Where would I look to see if that vent was re-routed? Would it be obvious or tricky to see without disassembly?

Click to expand...

Vark,

The easiest way to check, depending on model, is pull the air snorkel off the air cleaner box and look at the top of the block just behind the timming chain cover, dead center below the fan. There will be a 1/8" x 1" tall nipple coming up. If it still has a hose on it disappearing towards the rear of the engine, you still have the original venting. If the nipple is capped or plugged, at least half of the system has been correctly changed.

The other way to check, or to confirm that the other half of the system has been properly changed, is to lift the rear end of the fuel tank about 8". About 7" forward of the rear of the tank, in line with the right hand frame rail, will be two nipples hanging down from the bottom of the tank. The rear one is the filler cap rain drain and the forward one is the fuel tank vent. The easiest way to remember which is which is; the forward nipple hose goes forward to the nipple on the block and the rear nipple hose goes toward the rear to drain the rain water out by the foot peg plate. If any hoses are connected to these nipples or are laying around that area, the conversion has not been properly made.


The conversion entails installing "the cup" or what BMW calls the air accumulator: 16 13 2 307 467 AIR ACCUMULATOR $5.32.

This little rectangular cup clips to the intersection of the frame rails just below the two tank nipples. When the tank is dropped into position, the nipples are inside the cup. You take the hose that used to be the rain drain hose and hook it to the drain of the cup so that it will drain to behind the peg plate. The hose that used to be the tank vent gets removed along with the check valve that is in the middle of the hose and the nipple on top of the block gets capped or plugged. Any leakage at this nipple creates a vaccuum leak and a lean run condition, so it is critical that it is securely blocked!

The advantage to this system (other than no fuel or fuel vapors entering your oil) is that it makes removing and installing the fuel tank way easier. Two less hoses to remove and install and it eliminates the real possibility of kinking the tank vent hose when installing the tank. All for only $5!

98lee said:

The easiest way to check, depending on model, is pull the air snorkel off the air cleaner box and look at the top of the block just behind the timming chain cover, dead center below the fan. There will be a 1/8" x 1" tall nipple coming up. If it still has a hose on it disappearing towards the rear of the engine, you still have the original venting. If the nipple is capped or plugged, at least half of the system has been correctly changed.

The other way to check, or to confirm that the other half of the system has been properly changed, is to lift the rear end of the fuel tank about 8". About 7" forward of the rear of the tank, in line with the right hand frame rail, will be two nipples hanging down from the bottom of the tank. The rear one is the filler cap rain drain and the forward one is the fuel tank vent. The easiest way to remember which is which is; the forward nipple hose goes forward to the nipple on the block and the rear nipple hose goes toward the rear to drain the rain water out by the foot peg plate. If any hoses are connected to these nipples or are laying around that area, the conversion has not been properly made.


The conversion entails installing "the cup" or what BMW calls the air accumulator: 16 13 2 307 467 AIR ACCUMULATOR $5.32.

This little rectangular cup clips to the intersection of the frame rails just below the two tank nipples. When the tank is dropped into position, the nipples are inside the cup. You take the hose that used to be the rain drain hose and hook it to the drain of the cup so that it will drain to behind the peg plate. The hose that used to be the tank vent gets removed along with the check valve that is in the middle of the hose and the nipple on top of the block gets capped or plugged. Any leakage at this nipple creates a vaccuum leak and a lean run condition, so it is critical that it is securely blocked!

The advantage to this system (other than no fuel or fuel vapors entering your oil) is that it makes removing and installing the fuel tank way easier. Two less hoses to remove and install and it eliminates the real possibility of kinking the tank vent hose when installing the tank. All for only $5!

Click to expand...

Thank you for the detailed explanation. I followed it perfectly. Much appreciated.

chunk said:

They also added a little spring loaded flapper door at the opening. Not a big deal on a car, but a PIA on a bike. I don't know if all states have those accordion things on the pump nozzles that have to be held back as well, while trying to fill the tank. On my k75 I deleted the valve and capped it off at the crankcase, now the tank just vents to the atmosphere. Maybe sometime I might try to get rid of the flapper door as well.

Click to expand...

Chunk,



You really don't want to just leave the hose off the tank vent nipple, as it could drop raw fuel ontop of your hot engine (especially right after a fillup). Adding a hose to it is a little better, but it runs the risk of kinking every time you mess with the tank.

The fully correct way is to install "the cup". See post #9.


After, and only after, you have properly installed the cup, should you remove the flapper. Removing the flapper allows you to put slightly more fuel in the tank which puts more fuel closer to the venting system inside the tank which will put more raw fuel out the vent nipple after a fillup.

To remove the flapper, remove the four phillips screws that hold the filler neck to the tank. Remove and invert the filler neck and remove the three phillips screws that hold the flapper to the neck. Replace neck and you are done.

When you are filling up, stop at 3/8" from the bottom of the filler neck. Otherwise too much fuel will go out the vent and be wasted.
You will be able to fill easier, you will be able to visually check how much fuel is left in the tank (at stops, duh), and you will be able to monitor the condition (cleanliness) of the tank. All for only seven screws! (plus the $5 for "the cup).

98lee said:

Chunk,



You really don't want to just leave the hose off the tank vent nipple, as it could drop raw fuel ontop of your hot engine (especially right after a fillup). Adding a hose to it is a little better, but it runs the risk of kinking every time you mess with the tank.

The fully correct way is to install "the cup". See post #9.


After, and only after, you have properly installed the cup, should you remove the flapper. Removing the flapper allows you to put slightly more fuel in the tank which puts more fuel closer to the venting system inside the tank which will put more raw fuel out the vent nipple after a fillup.
To remove the flapper, remove the four phillips screws that hold the filler neck to the tank. Remove and invert the filler neck and remove the three phillips screws that hold the flapper to the neck. Replace neck and you are done.

When you are filling up, stop at 3/8" from the bottom of the filler neck. Otherwise too much fuel will go out the vent and be wasted.
You will be able to fill easier, you will be able to visually check how much fuel is left in the tank (at stops), and you will be able to monitor the condition (cleanliness) of the tank. All for only seven screws! (plus the $5 for "the cup).

Click to expand...

Thanks, I have the cup in my parts box, but when i removed the check valve i didn't know the cup existed, and just ran 2 seperate lines. Found out later and bought it. Next time the tanks off i will install the cup and run a single line down.
As far as the flapper, that's what i thought to remove it, thanks for confirming. That too at a later date.