Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Yamaha Tech
does a carb breath in or out or both? does a carb breath in or out or both?
Register FAQ Calendar Today's Posts
Yamaha Tech Originally the Yamaha XT600 Tech Forum, due to demand it now includes all Yamaha's technical / mechanical / repair / preparation questions.
Photo by Hendi Kaf, in Cambodia

I haven't been everywhere...
but it's on my list!


Photo by Hendi Kaf,
in Cambodia



Like Tree1Likes
  • 1 Post By steveloomis

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 26 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Sep 2002
Location: london,england
Posts: 191
does a carb breath in or out or both?
i was thinking or routing all the carb and fuel pump breather hoses (bar the drain and overflow) upwards into the airbox on my 1vj tenere. will the negative pressure in the 'box affect the carbs at all? has anyone done this?
cheers.
Reply With Quote
  #2  
Old 27 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Sep 2012
Location: Middle USA
Posts: 349
I would NOT do that. You need atmospheric pressure in the float bowl and elsewhere to work properly. If the air box was OK, Yamaha would have done that, especially on an off road bike....
__________________
'84 XT600 is now bored to 2nd oversize and new OEM pistons and rings installed. No more smoking.
Reply With Quote
  #3  
Old 31 Oct 2013
Registered Users
HUBB regular
  
Join Date: Oct 2013
Posts: 34
After having my bike dyno'd, the hoses used for equalizing the pressure in the bowl were not replaced by the shop, are these hoses necessary? Without these hoses will dirt and dust gain easier access to the interior of the carb? Mike
Reply With Quote
  #4  
Old 31 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Sep 2012
Location: Middle USA
Posts: 349
Those hoses are air vents and could suck in a little. I always run mine. You can use clear hose available at hardware stores, very cheap.
__________________
'84 XT600 is now bored to 2nd oversize and new OEM pistons and rings installed. No more smoking.
Reply With Quote
  #5  
Old 31 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Apr 2005
Location: Oxford UK
Posts: 2,116
Quote:
Originally Posted by steveloomis View Post
I would NOT do that. You need atmospheric pressure in the float bowl and elsewhere to work properly. If the air box was OK, Yamaha would have done that, especially on an off road bike....
In general I'd agree with that but there are always oddball exceptions. I'm running a CCM600 single with a DellOrto carb and if the breathers are anywhere but in the airbox the engine misfires briefly in conditions where you're hit with a wall of air - like overtaking a truck at speed for example and you go through the bow wave. A misfire at that point, when you're level with the cab, doesn't make for a relaxing ride

I'm sure that Mikunis etc are not that sensitive (or none of the ones I have on other bikes are anyway) but the breathers do actually do something even if on "properly" designed carbs you're unaware of it.
Reply With Quote
  #6  
Old 31 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Mar 2007
Location: UK
Posts: 4,343
Quote:
Originally Posted by tall-mike View Post
, are these hoses necessary? Without these hoses will dirt and dust gain easier access to the interior of the carb? Mike
I've always assumed that they deal mainly with any overflow from the float bowl, taking the volatile fuel away from the hot engine and down to the road level - I guess I came to this assumption via the number of times suchlike happened with my TTR600 carburettor.
__________________
Dave
Reply With Quote
  #7  
Old 31 Oct 2013
Registered Users
Veteran HUBBer
  
Join Date: Sep 2002
Location: london,england
Posts: 191
looks like im gonna be getting/ making some kind of filter for the breathers then. i also got a 1 way valve for the overflow. the bike sucks in water in deep puddles and in dry conditions a bit of dust finds itself into the carb through the breathers....
Reply With Quote
Reply

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
XT600E Carb Removal? Guest121 Yamaha Tech 25 30 May 2023 16:37
89 XT600 (kick start) Carb issue ajax Yamaha Tech 4 25 Oct 2013 19:02
Suzuki DRZ 400 SM - carb problems - can you help an overlander make it home? o_0oo Suzuki Tech 15 11 Jun 2013 18:23
Problem with my XT carb rich7 Yamaha Tech 3 10 Mar 2013 15:23

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now, and add your information if we didn't find you.

Next HU Eventscalendar

25 years of HU Events
Be sure to join us for this huge milestone!

ALL Dates subject to change.

2025 Confirmed Events:

Virginia: April 24-27
Queensland is back! May 2-5
Ecuador June 13-15
Germany Summer: May 29-June 1
CanWest: July 10-13
Switzerland: Date TBC
Ecuador: Date TBC
Romania: Date TBC
Austria: Sept. 11-14
California: September 18-21
France: September 19-21
Germany Autumn: Oct 30-Nov 2

Add yourself to the Updates List for each event!

Questions about an event? Ask here

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

Adventurous Bikers – We've got all your Hygiene & Protection needs SORTED! Powdered Hair & Body Wash, Moisturising Cream Insect Repellent, and Moisturising Cream Sunscreen SPF50. ESSENTIAL | CONVENIENT | FUNCTIONAL.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

Your ad could be here, on EVERY page of the HUBB, or the whole website, or as many as you like!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.



All times are GMT +1. The time now is 01:57.

Contact Us - Horizons Unlimited Motorcycle Travellers Website - Archive - Privacy Statement - Top