Draining the Lower Tank?

[gregu]

Has anyone drained the lower tank without removing the upper tank/connector hose etc? I have bad gas and want to remove all gas before refilling.
(Sounds like one DIY member was able to manipulate a small hose into upper tank through the connector and suck out the gas)
I would also assume from all diagrams available...there is no lower tank bleeder?
Thanks, Greg

 

[BakerBoy]

Greg, there's no drain from either tank. It seems possible to fish a hose past the upper tank fuel level float and through the angles & connections of the largest joint hose into the smaller tank [i.e., places to hang up the hose you're pushing through] ... but I suspect you'll not get all the fuel out and you risk damaging what proves to be a finicky upper tank fuel level float armature and encoder.

I would pause you though ... Is the fuel really bad? How do you know?

Presuming the fuel should be removed, there are 4 fuel connections on top of the bottom tank, numbered as follows in the following pictures:
1) the small hose that vents lower tank vapors into the upper tank
4) the large hose that connects to the upper tank (large enough to fill the lower tank quickly during fuel-ups)
5) pressurized fuel delivered out of the fuel pump to the fuel rail above the throttle bodies
6) depressurized excess fuel returned from the fuel rail

<note that hoses #1 and #4 are already removed in this picture
.

I suggest you NOT fish anything into the tank while trying to get through the #4 hose and connections. Instead, go after #1 connection to first get the upper tank empty. To do this, pinch off the #1 hose on the upper-tank side of the lower tank (have another like-sized hose and fuel container ready!), disconnect the #1 connection from the lower tank and promptly push on the temporary drain hose onto that #1 connection's nipple (the hose should drain, by gravity into the container). Open the gas cap to vent the upper tank. Once the fuel has stopped flowing, the upper tank should be empty. Then, disconnect #4 connection (it's a bear), reconnect #1 hose, fish a hose through the #4 connection into the lower tank and syphon the rest of the fuel. Reassemble using a NEW large #4 hose and clamp (or be really certain that yours is not damaged).

The above method will allow you to mostly drain the lower tank without having to remove the fuel pump (which, by the book, requires you to replace the lower fuel tank gasket). All things considered, you can't be sure the lower tank is totally empty UNLESS you remove the fuel pump assembly from the lower tank and look in.

 

[gregu]

Excellent reply. Yes I removed the #4 hose and fished a small diameter hose into the lower tank and presto...siphoning while I write.
Bad Gas? I had shoulder surgery and have not ridden for 3 months. Start it every 2 weeks but last start the exhaust smelled like varsol. I want to drain and fill with fresh before I get too far along. Probably another month before I can push it off the center stand. Thanks.

 

[BakerBoy]

If you removed the #4 hose without issue, you likely didn't have any/much fuel in the upper tank (otherwise fuel would have dumped everywhere, quickly).

FYI, you could have just seafoam treated the fuel; 3 mos is not too long (mine sits 6 mos). Especially since yours runs ... Exhaust smell isn't an indicator of fuel quality.

 

[Blrfl]

+1 on what John said. Fill the tank, add fuel stabilizer if you feel like it and then park it until you're ready to ride it again.

Unless you plan on giving the engine a good run, starting it is the worst thing you can do. And yes, the exhaust will stink when you first start it back up. Don't worry about it; it will go away after a ride.

--Mark

 

[Mick]

Unless you plan on giving the engine a good run, starting it is the worst thing you can do.

I've heard this before buy why specifically is this? As long as you brought your temp up long enough to boil away the moisture & acids in your oil, it would seem that it would not hurt. When I had each of my three shoulder surgeries, I could not ride for about 7 months each time. During my recoveries I started my bikes up about every three weeks to a month and let them run for a while after the radiator fan came on. Total time was 10 to 15 minutes, mostly at 1.5k to 1.8k rpm with a few spurts up up to 3.0k rpm. I also had Stabil in the gas.

I've just never felt comfortable letting my bikes sit for such long periods of time without starting them, even with fuel stabilizer in them. I'm even more of a believer in starting a stored bike occasionally after buying a low mileage ST last year that had apparently sat stored for long periods of time with E10 gas sitting in the lower tank resulting in a tank completely trashed by rust. For those who didn't see (or remember) my original posts on this, go here for pictures and here for the fix. It was not a pleasant experience.

 

[Blrfl]

I've heard this before buy why specifically is this? As long as you brought your temp up long enough to boil away the moisture & acids in your oil, it would seem that it would not hurt.

I just don't see a lot of point in running the engine without putting a load on it. Idling and higher speeds without a load gets rid of the low-hanging fruit without building up any of the pressures in the engine that you get when you're actually riding it. None of this stuff is doing the engine any harm sitting in the oil pan, and I'd sooner blow it all out once than getting rid of some portion of it, recirculating the rest through the engine, possibly adding more in the process and then repeating the cycle. If the oil's not getting fully heated, there's also more tendency for sludge build-up. I'm of the opinion that the temperature gauge isn't linear and that the engine does get hotter under load than it does at idle.

It's not backed by anything scientific, but that's my take on it.

I'm even more of a believer in starting a stored bike occasionally after buying a low mileage ST last year that had apparently sat stored for long periods of time with E10 gas sitting in the lower tank resulting in a tank completely trashed by rust.

I remember that thread, and that was a pretty big mess. The question that lingers in my mind is how the previous owner stored it.

My bike has gone through a number of months-long down periods in the last five years, many of which were with no fuel stabilizer, but always with the lower tank full. Since it'll be ten years old this spring, I may replace the fuel filter, and when I do I'll post up if find anything gross.

--Mark

 

[SupraSabre]

If you want to drain your tanks (both) completely (leaving only a small amount where the pump doesn't go), Remove the #6 hose in the picture above and QUICKLY attach a similar size hose to it leading to a very big gas can! Depending on how much gas you have in your tanks!

I've used this method now on all three of my bikes and let me tell you....

1. Have a big gas can with you!
2. There will not be any gas left in either tank.
3. Get a bigger gas can, that 3 gallon one ain't going to do it!
4. Be quick swapping the two hoses when you first start out. You will lose a littl gas, but the quicker you are, the less you lose!
5. Better get a bigger gas can than that! 4:

 

[dduelin]

I've heard this before buy why specifically is this? As long as you brought your temp up long enough to boil away the moisture & acids in your oil, it would seem that it would not hurt. When I had each of my three shoulder surgeries, I could not ride for about 7 months each time. During my recoveries I started my bikes up about every three weeks to a month and let them run for a while after the radiator fan came on. Total time was 10 to 15 minutes, mostly at 1.5k to 1.8k rpm with a few spurts up up to 3.0k rpm. I also had Stabil in the gas.

.

You answered your own question. Running under no load for 15 or 20 minutes does not heat the engine oil up to anywhere near 212 degrees so all this does is increase the likelihood of adding additional moisture into the sump from the heat/cool cycle. If the oil does approach 212 degrees it is at the very end of the engine run and does last long enough to remove any moisture.

 

[Mick]

You answered your own question. Running under no load for 15 or 20 minutes does not heat the engine oil up to anywhere near 212 degrees so all this does is increase the likelihood of adding additional moisture into the sump from the heat/cool cycle. If the oil does approach 212 degrees it is at the very end of the engine run and does last long enough to remove any moisture.

I don't quite get this. Load or not, the engine is still heating up enough to cause the radiator fan to come on. That heat is not just being transferred to what's in the cooling jackets. It's also being transferred to anything touching the engine block such as the oil. As a matter of fact, it would seem that the oil would heat up faster sitting still since there is no air flowing over the engine block (& therefore augmenting the water cooling a little bit) other than that caused by the radiator fan.

 

[dduelin]

It's been a long time since I had a car with an oil temp gauge but when I did I was surprised how long and how hard a car has to driven to get the oil over 200 degrees F never mind 220 or more. A fast idle might heat up the coolant to 180 fairly quickly but that heat does not transfer to the oil very quickly.

 

[gregu]

All-good stuff. Follow-up, I syphoned the gas through #4. Put in fresh gas with stabil. Started and ran rough for 2 minutes, then I could hear the change and ran oh so smooth.

Ran for 10 minutes with ravs ramped to 5 k a few times. The cases and exhaust were hot, fans ran once. Pulled the oil drain, the oil was warm...but not the screaming hot like when I ride and pull the drain. Evidence to support the no-start comments?

So, I went to the internet, found a Suzuki GS and Honda lay-up procedure. Both say: Ride it, then drain it. Refill cases to the brim with oil, oil each cylinder & turn over, fresh fuel to the brim with stabil, pull the battery. Neither say to start the bike during this 4+ month lay-up.

When it's time to ride, drain the storage oil, refill with proper oil and ride. That said...the Suzuki file mentions the acids in the oil and even admits that the storage oil will be contaminated but at least this method dilutes the acids. So, I would probably use the cheapest, light weight, non-detergent oil I could find for the storage.

Therefore, I now lean to not starting. I should have done the oil part. To the writer that suggested #6 hose: Does the gas come out of the #6 hose or the steel fitting to the tank flange? Thanks Greg

 

[Mick]

Ran for 10 minutes with ravs ramped to 5 k a few times. The cases and exhaust were hot, fans ran once. Pulled the oil drain, the oil was warm...but not the screaming hot like when I ride and pull the drain. Evidence to support the no-start comments?

So, I went to the internet, found a Suzuki GS and Honda lay-up procedure. Both say: Ride it, then drain it. Refill cases to the brim with oil, oil each cylinder & turn over, fresh fuel to the brim with stabil, pull the battery. Neither say to start the bike during this 4+ month lay-up.<SNIP>

Therefore, I now lean to not starting. I should have done the oil part. To the writer that suggested #6 hose: Does the gas come out of the #6 hose or the steel fitting to the tank flange? Thanks Greg

OK, I now be officially edjumacated! Between you and dduelin, I'm now a believer in not starting the bike while stored up.

I looked up the Suzuki storage procedure you mentioned. Here's the link to it in case anyone wants to look at it: http://suzuki.mcf.com/winterstorage.html

 

[Lost Dutchman]

If you want to drain your tanks (both) completely (leaving only a small amount where the pump doesn't go), Remove the #6 hose in the picture above and QUICKLY attach a similar size hose to it leading to a very big gas can! Depending on how much gas you have in your tanks!

Do you attach the temporary hose (to gas can) to the nipple on the tank - or - connect it to the hose from the fuel rail?

Thanks
Joe

 

[SupraSabre]

Do you attach the temporary hose (to gas can) to the nipple on the tank - or - connect it to the hose from the fuel rail?

Thanks
Joe

the nipple from the tank...That's where the gas will be coming from...

 

[Coasty]

the nipple from the tank...That's where the gas will be coming from...

I'm getting ready to ship my bike from Hawaii to Oregon and it will be sitting in a dark box for months so I need to get the fuel out of the lower tank. Do you start the bike to get the fuel to come out of the #6 hose or just turn the ignition on?

Thanks,
Patrick

 

[BakerBoy]

Coasty, fuel will drain by gravity (no power required) until it is below the level of that nipple. The lower tank will not be empty. Keep in mind that the fuel will drain from the nipple, not the hose. Open the gas cap on the upper tank while draining and you'll get best results.

 

[SupraSabre]

I'm getting ready to ship my bike from Hawaii to Oregon and it will be sitting in a dark box for months so I need to get the fuel out of the lower tank. Do you start the bike to get the fuel to come out of the #6 hose or just turn the ignition on?

Thanks,
Patrick

Neither. If you have gas in both tanks, the one connection will drain both of them down to almost, maybe a half of pint left. You don't even need to turn the ignition on for it to drain. Just don't stop it once it starts draining, so make sure you have a big enough container for what gas you have.


From my post from the first page:

If you want to drain your tanks (both) completely (leaving only a small amount where the pump doesn't go), Remove the #6 hose in the picture above and QUICKLY attach a similar size hose to it leading to a very big gas can! Depending on how much gas you have in your tanks!

I've used this method now on all three of my bikes and let me tell you....

1. Have a big gas can with you!
2. There will not be any gas left in either tank.
3. Get a bigger gas can, that 3 gallon one ain't going to do it!
4. Be quick swapping the two hoses when you first start out. You will lose a little gas, but the quicker you are, the less you lose!
5. Better get a bigger gas can than that!