Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Yamaha Tech
Yamaha Tech Originally the Yamaha XT600 Tech Forum, due to demand it now includes all Yamaha's technical / mechanical / repair / preparation questions.
Photo by Mark Newton, Mexican camping

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


Photo by Mark Newton,
Camping in the Mexican desert



Like Tree2Likes
  • 2 Post By Worsle

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 6 Jan 2018
Registered Users
New on the HUBB
 
Join Date: Mar 2015
Posts: 12
TTR600R carb pipe

Hi all - this is ref a TTR600 but am sure will be similar for other Yamaha thumpers.

My 2003 kick start TTR600 has been parked up a while in the garage and the other day i went in and there was a puddle of petrol underneath it.

I had a look and one of the pipes coming off the bottom of the carb had perished, but more to the point the small outlet on the bottom of the carb it was attached to, was dripping fuel. However, I'm unclear how fuel was getting through it so I hope someone can help?

On this handy diagram: https://www.motorcyclespareparts.eu/...or-346464.aspx you'll see part 20 - which is a small screw on the bottom of the carb - is it a jet or a drain screw?
In any case the small nub in front of that on the diagram is where its leaking from. Turning off the fuel stops it.

Any idea why it would be leaking / what I need to fix to stop it leaking?

Thanks!

Phil
Reply With Quote
  #2  
Old 6 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: May 2014
Location: Crete Greece
Posts: 105
Quote:
Originally Posted by Worsle View Post
Hi all - this is ref a TTR600 but am sure will be similar for other Yamaha thumpers.

My 2003 kick start TTR600 has been parked up a while in the garage and the other day i went in and there was a puddle of petrol underneath it.

I had a look and one of the pipes coming off the bottom of the carb had perished, but more to the point the small outlet on the bottom of the carb it was attached to, was dripping fuel. However, I'm unclear how fuel was getting through it so I hope someone can help?

On this handy diagram: https://www.motorcyclespareparts.eu/...or-346464.aspx you'll see part 20 - which is a small screw on the bottom of the carb - is it a jet or a drain screw?
In any case the small nub in front of that on the diagram is where its leaking from. Turning off the fuel stops it.

Any idea why it would be leaking / what I need to fix to stop it leaking?

Thanks!

Phil
That overflow valve is doing what it is supposed to be doing... It's leaking to prevent excess fuel mixture into the cylinder, preventing it from doing a hydraulic combustion... You shouldn't be focusing on that... Your real problem is inside the carburetor... If it could guess I would say it has to with the floating device inside the carburetor... It always on a downward position so it would keep adding more fuel inside, thus causing the overall overflow... But this is just a quick guess since we can't see what's going on inside there...

Sent from my MI 5 using Tapatalk
Reply With Quote
  #3  
Old 6 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: May 2014
Location: Crete Greece
Posts: 105
Quote:
Originally Posted by Worsle View Post
Hi all - this is ref a TTR600 but am sure will be similar for other Yamaha thumpers.

My 2003 kick start TTR600 has been parked up a while in the garage and the other day i went in and there was a puddle of petrol underneath it.

I had a look and one of the pipes coming off the bottom of the carb had perished, but more to the point the small outlet on the bottom of the carb it was attached to, was dripping fuel. However, I'm unclear how fuel was getting through it so I hope someone can help?

On this handy diagram: https://www.motorcyclespareparts.eu/...or-346464.aspx you'll see part 20 - which is a small screw on the bottom of the carb - is it a jet or a drain screw?
In any case the small nub in front of that on the diagram is where its leaking from. Turning off the fuel stops it.

Any idea why it would be leaking / what I need to fix to stop it leaking?

Thanks!

Phil
Your problem would be on 4 or 42 according to your diagram...

Sent from my MI 5 using Tapatalk
Reply With Quote
  #4  
Old 6 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: Mar 2007
Location: UK
Posts: 4,343
TTR600 - got to love them

When I owned one of these bikes, it did much the same thing i.e. overflowing from the carb.

When you are finished riding the bike, turn off the fuel tap and run the engine until it dies on you i.e. until the float bowl has run out of fuel. This does deal, to some extent, with the problem you describe and, more long term, it limits the tendency for the fuel to evaporate from the carb and leave gummy deposits in those "hard to get at" small bits inside the carb.
It's not exactly vital to practice this procedure for short term stops but it is a great procedure to use when the bike is to be laying around for a while without the engine being run.
But, some people say that if the float is left "not floating" for a long time then it can jam in that position, so you have to make a decision on that point for yourself.

Regarding your precise current problem, it is probably caused by an issue with the float bowl - if out of adjustment it allows fuel to overflow.
__________________
Dave

Last edited by Walkabout; 6 Jan 2018 at 15:53. Reason: TTR600 - got to love them
Reply With Quote
  #5  
Old 6 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: May 2013
Location: Wisconsin, USA
Posts: 827
There is an o-ring underneath the brass part(seat) that the float needle goes in and seals off the flow of gas coming in when the float is at the set level . Those o-ring get hard and crack , usually from age and certain gas formulas . They will allow gas to bypass the needle and overfill the bowl . That would be first go-to item to replace , even if it "looks" ok , and install a Viton version that can handle fuel , especially ethanol , better than the std , Buna-N o-ring that is in there now .



.
__________________
'86 XT600/3TB motor,,, '88 XT600, ,,'92 XT600e,,, '08 Husky TE510,,, '05 DRZ463,,, '95 KLX650 ,,,'96 KLX650
Reply With Quote
  #6  
Old 7 Jan 2018
Registered Users
New on the HUBB
 
Join Date: Mar 2015
Posts: 12
Thanks all - thats a great help. Sounds like I'd better get the carb off and investigate those two items you mention.
Reply With Quote
  #7  
Old 7 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: Mar 2007
Location: UK
Posts: 4,343
Quote:
Originally Posted by Worsle View Post
Hi all - this is ref a TTR600 but am sure will be similar for other Yamaha thumpers.
Actually, there are differences which is why this sub-section was broadened a few years ago (I suppose the other option was to have a stack of sub-sections related to each of the vast range of yamaha products - of which I have owned a few!!).

"Originally the Yamaha XT600 Tech Forum, due to demand it now includes all Yamaha's technical / mechanical / repair / preparation questions"
__________________
Dave
Reply With Quote
  #8  
Old 24 Apr 2018
Registered Users
New on the HUBB
 
Join Date: Mar 2015
Posts: 12
Sure enough it was the float valve - the ring had hardened. While I was at it I found the pilot jet to be partially blocked and also a fair bit of crap above the little gauze filter as well - so gave it all a good clean and service. Thank you everyone for your help - now I've read about carburettors it was all pretty obvious!
Reply With Quote
Reply


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
single carb xt600 2003 nickargas Yamaha Tech 2 3 Jan 2018 10:03
Carb adjustment lost frozenbiker Yamaha Tech 3 12 May 2016 13:43
Yamaha XT 600 single carb + KTM shock - How it was made Svaneberg Yamaha Tech 80 21 Dec 2014 17:58
Xt550 carb issues / carb swap vm28's wetcoastrider Yamaha Tech 0 21 Feb 2014 14:10
89 XT600 (kick start) Carb issue ajax Yamaha Tech 4 25 Oct 2013 18:02

 
 

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

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

2025:

  • Queensland is back! Date TBC - May?

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

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...

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!

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 06:48.