Author Topic: where does this cut tube go to?  (Read 1130 times)

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Offline juntjoo

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where does this cut tube go to?
« on: March 18, 2018, 07:52:50 PM »
cut tube next to battery https://imgur.com/a/O4Bz4

it's related to the battery, I'm assuming for electrolyte overflow or something, but I couldn't find in the fiche but it's some enclosure below the air box. a couple tubes go there.
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline PeWe

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Re: where does this cut tube go to?
« Reply #1 on: March 18, 2018, 10:50:39 PM »
Old batteries had a ventilation pipe going out where a clear tube was attached going down. Earlier bikes had this pointing at the drive chain which could get acid and snapped, cases broken. If the bike will fall, acid will flow out from it dripping on the swing arm where the hose might be aiming at. That's how the paint will disappear from that area causing craters with rust.

The tube from battery is most likely to be put inside that black hose.

My GEL battery I use have no pipe going out at all.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
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http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
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Offline juntjoo

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Re: where does this cut tube go to?
« Reply #2 on: March 19, 2018, 01:17:56 AM »
Old batteries had a ventilation pipe going out where a clear tube was attached going down. Earlier bikes had this pointing at the drive chain which could get acid and snapped, cases broken. If the bike will fall, acid will flow out from it dripping on the swing arm where the hose might be aiming at. That's how the paint will disappear from that area causing craters with rust.

The tube from battery is most likely to be put inside that black hose.

My GEL battery I use have no pipe going out at all.

thanks. yeah, that's the kind of battery i have and i believe all my corrosion was from the last one I didn't insert the tube with. but where does it end up? i can see something but I don't know what it is and i think other tubes are going in it
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Bodi

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Re: where does this cut tube go to?
« Reply #3 on: March 19, 2018, 03:31:17 AM »
The thing below the air box is a separator, it takes oil out of the crankcase vent gas while the rest goes back into the carb intakes. No connection to the battery. The battery vent, for non-sealed batteries, just goes diectly down to hang open below the swingarm pivot.

Offline juntjoo

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Re: where does this cut tube go to?
« Reply #4 on: March 19, 2018, 03:36:32 AM »
The thing below the air box is a separator, it takes oil out of the crankcase vent gas while the rest goes back into the carb intakes. No connection to the battery. The battery vent, for non-sealed batteries, just goes diectly down to hang open below the swingarm pivot.

ah okay, thanks
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline KeithB

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Re: where does this cut tube go to?
« Reply #5 on: March 19, 2018, 04:08:40 AM »
 For those that have a vented battery, it's important that those vent tubes hang well below the bike and away from frame components.
Don't ask how I know ::)
Nanahan Man

Offline Phinn

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Re: where does this cut tube go to?
« Reply #6 on: March 19, 2018, 05:53:38 AM »
For those that have a vented battery, it's important that those vent tubes hang well below the bike and away from frame components.
Don't ask how I know ::)

This is definitely good advice.

However, also remember that this tube (usually clear on modern batteries) vents out battery gases, especially when it’s warm and fully charged.

I was grinding a part of my frame once, down by the foot pegs, when a spark flew across the open end of this battery vent tube. The battery exploded, blowing the lid off and shooting battery acid straight up. I was crouched down below the lid of the battery, so I was fine, but if I’d been looking down at it, I’d have been blinded and/or permanently scarred.

Don’t do any grinding or welding near a lead-acid battery or its vent tube.
« Last Edit: March 19, 2018, 05:56:40 AM by Phinn »
1978 CB750K -- "Mouse," a former basket case, resurrected

Offline jlh3rd

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Re: where does this cut tube go to?
« Reply #7 on: March 19, 2018, 05:57:02 AM »
Does this help?