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 Alessio Corradini, on the Salar de Uyuni, Bolivia, of two locals

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


Photo by Alessio Corradini,
on the Salar de Uyuni, Bolivia,
of two locals



Like Tree4Likes

Reply
 
LinkBack Thread Tools Display Modes
  #46  
Old 23 Jan 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Guys I have a question that might solve my issue.

Please take a look at the o-ring in this picture where does it actually go ? what is the correct placement for it ?



Thanks !
Reply With Quote
  #47  
Old 24 Jan 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Does it go in the groove on the screw ? what is it's purpose to stop a gasoline leak ?
Reply With Quote
  #48  
Old 24 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: Feb 2005
Location: uk
Posts: 217
hi have a look at answer 4 hope this helps steve
http://www.horizonsunlimited.com/hub.../backfire-5560
Reply With Quote
  #49  
Old 24 Jan 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Thanks ! I re-fitted a new o-ring in the correct place. The old one was broken in 2 pieces and worn out. Now the idle mixture screw is actually working and I could tune it (with warm engine) to have the best mixture. (it was betweem 2.5 and 3 turns out).

The starting problem is still there and I think the choke circuit might be clogged up a bit !

The rpm raise with choke but not too much maybe close to 2000 rpm and I've seen on the internet that some bikes when choke is pulled rev towards 2500-2800 rpm ... this could be one of my problems since the idling immediately after starting happened only when the weather got colder (0 degrees C and bellow)

Do you happen to know if it's possible to remove only the lower part from the carburettor without taking them off from the bike ? It's freezing outside and I work at -10 degrees C.

Would be nice if removing of the float bowl is possible without taking of the carbs.

Thanks !

Reply With Quote
  #50  
Old 26 Jan 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
I took the carbs off again today and cleaned them really well and also cleaned the choke mechanism (found some black debris in there at the tip and around it).

The bike started perfectly at -10 degrees Celsius and idles without any problems.

I should have done this sooner but since I've cleaned the carbs two times in the past few months I couldn't believe anything could be clogged up. I use an inline fuel filter now and I swear I will never allow unfiltered gas to reach the carbs.

I used 2 cans of carb cleaner but I'm happy that it works so nicely now !

Idle is stronger and the mixture screw works spot on ! Also the choke was loose before and now it takes a little bit of force to pull/push it (not sure why).

Thread can be closed ! Problem was solved and I'm a little bit ashamed that I failed so many times to find such an easy fix.

I would like to thank all of you who posted and tried to help me out !

Bernek
Reply With Quote
  #51  
Old 29 Jan 2018
Registered Users
Veteran HUBBer
 
Join Date: Dec 2008
Location: Denmark
Posts: 1,417
Happy riding!
Reply With Quote
  #52  
Old 4 Mar 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Quote:
Originally Posted by Jens Eskildsen View Post
Happy riding!
I figured out something interesting today !

I cleaned the carbs again and they are pristine now. The float level is 27mm and the book says 25-27mm. It start better recently but not the perfect way.

So do you think those 2 mm are that important ? (bowl fuel level).

I also made another discovery ... I took of the seat off and covered the air intake scoop with my hand while starting to create a bigger vacuum than normal to check for a lean condition.

It's still running lean !! (at least at startup). The bike started and revved up immediately at -15 C degrees Celsius (it was standing there for 2 weeks no start during that time).

So I'm really lean but the question is:

Is the choke mechanism at fault ? or the pilot jet is way too small ? (I'm using the original jet.)

I have a full carburettor repair kit in mail waiting for it to arrive. With higher idle jet and all the rest.

But I don't know how to test the choke mechanism ... it clearly makes a difference with it pulled out or pushed in. In the past (2-3 months ago) I remember if I was pulling it out the bike would start to hiccup and almost die when fully warmed up.

I also made another discovery that improved the starting immediately. I flooded the carbs due to the fact that the float valve wasn't closing and it was dripping from the overfill hose. The bike started perfectly again (even with fuel flowing from the overfill ... so again I'm too lean and this points me to fuel level in bowl).

A little too many equations for me recently

Can someone with better knowledge and experience help ?

THANKS !
Reply With Quote
  #53  
Old 4 Mar 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Quote:
Originally Posted by jjrider View Post
As said that mixture screw is maybe equal to 1/2 jet size , you need a bigger pilot jet . The 48 should be fine , I can't remember what I have in all of mine but I know none are bigger than a 48 , more like 45 . You could have an airleak somewhere which is requiring a bit more fuel to make up for it . otherwise your fuel can just be that way and require a richer mixture. If you have a set of jet drills you can drill out the 48 about .001" and then file a slash across the number to remind you it has been drilled , I've done that a few times if it saves a bunch of messing around.

I generally have my idle set up around 1700-1800 , too low and these big singles get hard to keep running .


.
How does the 48 jet size translate into measurement units ? is it 0.48 mm ?
Reply With Quote
  #54  
Old 5 Mar 2018
Registered Users
Veteran HUBBer
 
Join Date: Dec 2008
Location: Denmark
Posts: 1,417
Wait till you get the repair kit. Its not easy to know whats going on if the float valve isnt sealing.

A #48 jet should be 0.48mm, so if its not enough, you can drill it to 0.5mm afterwards.

We just had -8c and my bike struggled a bit aswell, since it hadnt been started in a few weeks. For me, luckily all thats needed is fresh battery, as its 5 years old.

The engine doesn need much air at idle, so blocking the snorkel partially, or even fully removing it, wont make much, if any difference in tickover.
Reply With Quote
  #55  
Old 5 Mar 2018
Registered Users
Veteran HUBBer
 
Join Date: May 2013
Location: Wisconsin, USA
Posts: 827
The jet number isn't always the hole size , they often go by flow rate , but not all are rated the same , I don't know offhand which ones went more to the hole size but either way I think it comes out close , it's always best to stay with 1 brand when changing jets .http://www.historicmotorcycle.org.au...carby/jets.txt

http://www.jetsrus.com/FAQs/FAQ_miku...ihin_sizes.htm



Putting you hand over the air intake side of a carb is an old trick to force fuel up into the motor. The motor is creating vacuum and if it can't come through the carb bore it tries to come through any hole it can thus really pulls the fuel in , doesn't indicate a sign it's running lean though .
__________________
'86 XT600/3TB motor,,, '88 XT600, ,,'92 XT600e,,, '08 Husky TE510,,, '05 DRZ463,,, '95 KLX650 ,,,'96 KLX650
Reply With Quote
  #56  
Old 5 Mar 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Quote:
Originally Posted by jjrider View Post
The jet number isn't always the hole size , they often go by flow rate , but not all are rated the same , I don't know offhand which ones went more to the hole size but either way I think it comes out close , it's always best to stay with 1 brand when changing jets .http://www.historicmotorcycle.org.au...carby/jets.txt

FAQ Mikuni vs keihin vs dynojet



Putting you hand over the air intake side of a carb is an old trick to force fuel up into the motor. The motor is creating vacuum and if it can't come through the carb bore it tries to come through any hole it can thus really pulls the fuel in , doesn't indicate a sign it's running lean though .
I just obstructed the air intake a little bit. Less air more fuel ? why isn't that a sign for a lean mixture ? Please explain me ! I didn't block it completely just allowed less air to enter and it started like it should have and it ticked over really nicely. After 5 seconds I could remove my hand and it was idling nicely on choke...

I'm a bit lost now... I'm not going to drill the jets yet and the valve and seat for the bowl is closing perfectly (it has been changed 2-3 months ago by me brand new) but from time to time when I remove the carbs they leak until I kick it into place with the wood part of a hammer just smack the carb 2-3 times (easily) and it starts working.

Aren't all these sign showing me the lean condition at starting at least ?
Reply With Quote
  #57  
Old 5 Mar 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Quote:
Originally Posted by Jens Eskildsen View Post
Wait till you get the repair kit. Its not easy to know whats going on if the float valve isnt sealing.

A #48 jet should be 0.48mm, so if its not enough, you can drill it to 0.5mm afterwards.

We just had -8c and my bike struggled a bit aswell, since it hadnt been started in a few weeks. For me, luckily all thats needed is fresh battery, as its 5 years old.

The engine doesn need much air at idle, so blocking the snorkel partially, or even fully removing it, wont make much, if any difference in tickover.
Valve and seat are new ! I changed them few months back. Read my previos post please.

At least for me it makes a huge difference in starting. Without blocking the air intake partially it turns over more times and it starts and dies after 1-2 seconds. If I block it partially it starts faster and idles (doesn't die) nicely. I can remove the hand after a few seconds and it runs good on the choke !
Reply With Quote
  #58  
Old 5 Mar 2018
Registered Users
Veteran HUBBer
 
Join Date: Dec 2008
Location: Denmark
Posts: 1,417
I have, but I also read where you just talked about overflowing carbs, thats why i recommended to change the valve and seat.

After that you explained that it was only after installation (but still sounds like a regular thing for you) Its pretty hard to guess theese things.

Let us know how the #48 idle jet works out for you. That woudl be the next step. As for the choke, just make sure the passageways are clear, and the rubberbits on the choke-plunger itself is in good nick
Reply With Quote
  #59  
Old 6 Mar 2018
Registered Users
HUBB regular
 
Join Date: Nov 2017
Posts: 45
Quote:
Originally Posted by Jens Eskildsen View Post
I have, but I also read where you just talked about overflowing carbs, thats why i recommended to change the valve and seat.

After that you explained that it was only after installation (but still sounds like a regular thing for you) Its pretty hard to guess theese things.

Let us know how the #48 idle jet works out for you. That woudl be the next step. As for the choke, just make sure the passageways are clear, and the rubberbits on the choke-plunger itself is in good nick
I can't wait to test with the #48 myself ! About the choke I will try my best. Have to look for a sectional photo somewhere so I know which passageways it has and how it works. This is very important to starting and I can't say that I'm 100% sure that it works as it should

I guess with the idle jet swap I will work harder on the choke and see the results.

Thanks again !
Reply With Quote
  #60  
Old 6 Mar 2018
Registered Users
Veteran HUBBer
 
Join Date: May 2013
Location: Wisconsin, USA
Posts: 827
When you take the bowl off there is a brass tube that sticks down into a hole in the bowl itself , there should be an o-ring around it. There is a small hole at the bottom of the bowl next to that tube hole that must be open so fuel from the bowl can fill it. That tube is what feeds the choke . It is common for that little hole to get plugged if fuel has dried out at some point and is really hard to get open again .

None of these motor should need bigger than a #48 pilot and that's even a bit big from all the XT's I've had but it may be possible . There is a couple small feeder passages on these carbs that if partial blocked will cause hard starting cold , they're kind of a fussy design.


.
__________________
'86 XT600/3TB motor,,, '88 XT600, ,,'92 XT600e,,, '08 Husky TE510,,, '05 DRZ463,,, '95 KLX650 ,,,'96 KLX650
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 2 (0 Registered Users and/or Members and 2 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
yamaha xt600e 2002 turns over but won't starting raylock Yamaha Tech 2 5 Mar 2017 23:15
Yamaha Service Repair Manuals PDF martinanderson Yamaha Tech 0 31 May 2016 00:25
My XT600E Electric Start problems skiepi Yamaha Tech 23 8 Mar 2015 18:09
Carburettor problems XT600E - 3tb. carlhenrik_80 Yamaha Tech 13 26 Sep 2012 00:09
97' XT600E start failing / starting circuit cutoff relay p/n ? jamesahkXT600e Yamaha Tech 1 9 Jun 2012 03:43

 
 

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

ALL Dates subject to change.

2025 Confirmed Events:

  • Virginia: April 24-27 2025
  • Queensland is back! May 2-4 2025
  • Germany Summer: May 29-June 1 2025
  • CanWest: July 10-13 2025
  • Switzerland: Date TBC
  • Ecuador: Date TBC
  • Romania: Date TBC
  • Austria: Sept. 11-15
  • California: September 18-21
  • France: September 19-21 2025
  • Germany Autumn: Oct 30-Nov 2 2025

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!

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 08:07.