airheads and water crossings. - Page 4

bgoodsoil · 11-29-2012, 04:17 PM

Thanks, Thomas. I guess I'll stick with the high pipe. Now if I can find an aluminum version maybe I could drop a few pounds.

disston · 11-29-2012, 06:04 PM

The two small holes are breather holes. If you look inside the float bowl area up into the main body of the carb right below where these holes are yo see two more holes inside the main carb body. One of these can be plugged inside the float bowl area and the other vented to your hose. You should be OK with just one.

Box'a'bits · 11-29-2012, 06:52 PM

Here's some photos of variants in the 40mm carb. These come from here. Ironically it was Igormortis who made me aware of this site when I was having jetting issues & was considering using an air fuel meter.

Bing - 123, no idea where the breather vent is, sorry. Might still be the bottom of the float bowl?
Bing - 123a, vent is just below the plastic bing cover

Bing - 123a2. Breather port is the big cap above the riveted bing plate, & near the inlet. Looks like it would be relatively easy to take the cap off, & put a breather tube on that, or to create a spigot to take the breather much higher on the bike.

Thomas B. · 11-29-2012, 10:18 PM

Hay Prutser,
another question. When you drown your bike on the Sibirsky trip your air filter probably got soaked. Were you using the standart paper one? Did you change and dry it? Or just ran the wet one?
Never had my bike that deep in the water yet so I'm curiose.
thanks for the answer.
cheers Thomas

P.S. My carbs are 32s from a R80G/S so I have the breathertube in the float bowl.

Prutser · 11-30-2012, 02:11 AM

Quote:

Originally Posted by Thomas B.

Hay Prutser,
another question. When you drown your bike on the Sibirsky trip your air filter probably got soaked. Were you using the standart paper one? Did you change and dry it? Or just ran the wet one?
Never had my bike that deep in the water yet so I'm curiose.
thanks for the answer.
cheers Thomas

P.S. My carbs are 32s from a R80G/S so I have the breathertube in the float bowl.

After succesfully drowning my old gs i learned NOT to use the paper filter. Since soon after the drowning mushrooms start to grow in there

. And sand wil wear through the paper.

I was using a uni filter (foam) ! The problem with those is that they don't seal very well. Dirt is being sucked through between the airbox and the filter. To solve this I used a original filter, took out the paper and mounted the uni on top of the original filter. Made some longer clips to lock them together.

Now my air intake was against the bottom of my fuel tank.

A big problem that I would like to take care of is the water getting in when you make a big bow wave.
That was washing the dirt through the filter.

Airhead Wrangler · 11-30-2012, 02:10 PM

Just noticed this in the Baja GS replica thread:

Phreaky Phil · 11-30-2012, 03:11 PM

Here's my filter setup. Made for me by these guys http://www.uniflow.com.au/

Yes I know, its a bit dirty

With the top lifted off. Still nice and clean underneath.

The underside. They use your old paper filter, cut the guts out of it and fit their own. As the fillter is flat, spares can be carried without taking up much space. I used to find with the paper filters there would always be a fine layer of dust on the inside of the airbox. Not so with the foam type.

Prutser · 12-02-2012, 01:55 PM

Quote:

Originally Posted by Phreaky Phil

Here's my filter setup. Made for me by these guys http://www.uniflow.com.au/
They use your old paper filter, cut the guts out of it and fit their own. As the fillter is flat, spares can be carried without taking up much space. I used to find with the paper filters there would always be a fine layer of dust on the inside of the airbox. Not so with the foam type.

That's a much better set-up than the ones for sale over here. Really like the pre-filter and easy to wash top.
The ones they sell over here have a soft rubber outside that slides of the edge of the air box.

I'm thinking about trying this.

And put some waterproof pre-filters over them when doing river crossings to deal with the splashing of a bow wave.

igormortis · 12-02-2012, 03:25 PM

Some good ideas here.

Does anyone know if the standard airbox is the tuned, resonant type? Some reports seem to suggest that it is, due to loss of midrange torque when you start hacking holes in it.

I would be keen to modify the airbox to better deal with water, so long as the original characteristics can be maintained, or improved!

hardwaregrrl · 12-02-2012, 03:25 PM

Quote:

Originally Posted by Prutser

After succesfully drowning my old gs i learned NOT to use the paper filter. Since soon after the drowning mushrooms start to grow in there

. And sand wil wear through the paper.

I was using a uni filter (foam) ! The problem with those is that they don't seal very well. Dirt is being sucked through between the airbox and the filter. To solve this I used a original filter, took out the paper and mounted the uni on top of the original filter. Made some longer clips to lock them together.

Now my air intake was against the bottom of my fuel tank.

A big problem that I would like to take care of is the water getting in when you make a big bow wave.
That was washing the dirt through the filter.

I've got the same problem with the UNI. Always wondered if there was a way to turn the horns, maybe with some vinyl hose and some how make it bend 90 degrees out to the sides, maybe put a bologna slice on the end so it will keep the water out. Rooney made it look very complicated....

igormortis · 12-02-2012, 03:30 PM

Quote:

Originally Posted by hardwaregrrl

Always wondered if there was a way to turn the horns...

I keep meaning to check if there's space for the cover to be mounted backwards.

bgoodsoil · 12-02-2012, 06:44 PM

I want to see the pics when somebody sinks their G/S so deep that they need their air filter that high.

igormortis · 12-02-2012, 06:57 PM

Quote:

Originally Posted by bgoodsoil

I want to see the pics when somebody sinks their G/S so deep that they need their air filter that high.

11-29-2012, 04:17 PM	#46
bgoodsoil Dare to be Stupid Joined: Jul 2008 Location: Atlanta, GA, USA Oddometer: 3,888	Thanks, Thomas. I guess I'll stick with the high pipe. Now if I can find an aluminum version maybe I could drop a few pounds. __________________ '85 BMW r80G/S--Another G/S on the road--Central America on a Shoestring--Nova Scotia on a Shoestring--Never Leave a Man's Behind Proud SmugMug User Support ADV: Don't give those cheap bums your discount code

11-29-2012, 06:04 PM	#47
disston ShadeTreeExpert Joined: Mar 2011 Location: Silver Spring, Md Oddometer: 5,229	The two small holes are breather holes. If you look inside the float bowl area up into the main body of the carb right below where these holes are yo see two more holes inside the main carb body. One of these can be plugged inside the float bowl area and the other vented to your hose. You should be OK with just one. __________________ Never memorize something you can look up. ---Albert Einstein

11-29-2012, 06:52 PM	#48
Box'a'bits In need of repair Joined: Sep 2008 Location: Wellington, New Zealand Oddometer: 1,460	Here's some photos of variants in the 40mm carb. These come from here. Ironically it was Igormortis who made me aware of this site when I was having jetting issues & was considering using an air fuel meter. Bing - 123, no idea where the breather vent is, sorry. Might still be the bottom of the float bowl? Bing - 123a, vent is just below the plastic bing cover Bing - 123a2. Breather port is the big cap above the riveted bing plate, & near the inlet. Looks like it would be relatively easy to take the cap off, & put a breather tube on that, or to create a spigot to take the breather much higher on the bike. __________________ My '91 R100GS thread is here My Ride photos are here It's just better when there's twins involved.... Box'a'bits screwed with this post 11-29-2012 at 07:00 PM

11-30-2012, 02:10 PM	#51
Airhead Wrangler More tacos than you Joined: Mar 2008 Location: Manzanillo MX, occasionally Seattle Oddometer: 5,205	Just noticed this in the Baja GS replica thread: __________________ R80ST Gets The HPN Treatment Ducati Pantah 500SL Rebuild Seattle to TDF on an airhead WTB R100R Mystic sidestand and mount.

12-02-2012, 03:25 PM	#54
igormortis Beastly Adventurer Joined: Dec 2006 Location: Moving further away from Wellington, New Zealand Oddometer: 1,096	Some good ideas here. Does anyone know if the standard airbox is the tuned, resonant type? Some reports seem to suggest that it is, due to loss of midrange torque when you start hacking holes in it. I would be keen to modify the airbox to better deal with water, so long as the original characteristics can be maintained, or improved! __________________ Operation: Battle Panda

11-29-2012, 10:18 PM	#49
Thomas B. desert racer Joined: Feb 2010 Location: Switzerland and around the globe Oddometer: 56	Hay Prutser, another question. When you drown your bike on the Sibirsky trip your air filter probably got soaked. Were you using the standart paper one? Did you change and dry it? Or just ran the wet one? Never had my bike that deep in the water yet so I'm curiose. thanks for the answer. cheers Thomas P.S. My carbs are 32s from a R80G/S so I have the breathertube in the float bowl.

11-30-2012, 03:11 PM	#52
Phreaky Phil Beastly Adventurer Joined: Mar 2006 Location: NEW ZEALAND Oddometer: 1,216	Here's my filter setup. Made for me by these guys http://www.uniflow.com.au/ Yes I know, its a bit dirty With the top lifted off. Still nice and clean underneath. The underside. They use your old paper filter, cut the guts out of it and fit their own. As the fillter is flat, spares can be carried without taking up much space. I used to find with the paper filters there would always be a fine layer of dust on the inside of the airbox. Not so with the foam type.

12-02-2012, 06:44 PM	#57
bgoodsoil Dare to be Stupid Joined: Jul 2008 Location: Atlanta, GA, USA Oddometer: 3,888	I want to see the pics when somebody sinks their G/S so deep that they need their air filter that high. __________________ '85 BMW r80G/S--Another G/S on the road--Central America on a Shoestring--Nova Scotia on a Shoestring--Never Leave a Man's Behind Proud SmugMug User Support ADV: Don't give those cheap bums your discount code

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