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 Daniel Rintz, Himba children, Namibia

The only impossible journey
is the one
you never begin

Photo by Daniel Rintz,
Himba children, Namibia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 4 Dec 2003
Registered Users
Veteran HUBBer
 
Join Date: Aug 2003
Location: Perth
Posts: 263
crackle and pop

The old XT is playing up again, there seems to be a carbouration problem. It seems as if the carb is moving in time to the engine (back and forth) and thus the manifold is loose. It runs OK at high revs but when left to tick over it seems to every 30 seconds or so explode or pop.
it sounds as if air is being pushed back to the carb, its only on the right side (secondary carb). could an air leak from the loose manifold do this?

Ive tried tightening but it seems to be knackered however I don't want to replace it if it's not the problem. again other than that it goes fine but may get hot if I leave the choke out at lights (to keep it ticking over at 2500 rpm)

any thoughts appreciated
Reply With Quote
  #2  
Old 4 Dec 2003
Steve Pickford's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2003
Location: Oxford, UK
Posts: 994
If the rubber inlet manifold is "pulsing" in tune with engine revs, then there's nothing to worry about. On the inlet stroke, the engine is sucking in a lot of air, especially on a single. Lots of bikes do it to a lesser or greater extent, nothing more than the walls of the inlet manifold flexing.

If the manifold is tight to the head & the carbs are tight in the manifolds,then you may be running slightly lean. Try adjusting the mixture screw on the underside of the carb. Screwing it out in 1/8 turn increments will richen the mixture.

If problem still persists, check the air filter & exhaust fitment or alternatively, buy my R80GS....

Steve
__________________
My photos: www.possu.smugmug.com
Reply With Quote
  #3  
Old 4 Dec 2003
Registered Users
Veteran HUBBer
 
Join Date: Jan 2001
Location: Stockholm
Posts: 651
Seems like lean mixture, and the fact that it suddenly appeared leads to the diagnosis that the inlet rubber has come loose from the piece of metal that it is vulcanised to. And this piece of metal is bolted to the head. So, there is a gap between rubber and metal, the rubber moves slightly with the pulsating pressure in the inlet and the gap lets in air that has not passed the carb.
A test I have heard of: spray a little engine starter stuff around the rubber. If, at idle speed, the engine speed increases, the inlet rubber is defect. No tinkering, buy a new one.
This is a common prob with the XT6.

Auke
__________________
Auke
http://aukemarieke.blogspot.com
Reply With Quote
  #4  
Old 4 Dec 2003
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2002
Posts: 284
Last year, I discovered a hell of a lot of carbon in my carb.
On investigation I discovered that the previous owner had lengthened the cam-chain tensioner by welding a bolt onto the end of it.
This resulted in a stretched cam-chain, over advancing the timing and causing exhaust gases to blow up into the carb.
May be worth checking your timing, perhaps it's just slightly out?

Geoff
Reply With Quote
  #5  
Old 5 Dec 2003
Registered Users
Veteran HUBBer
 
Join Date: May 2003
Location: England
Posts: 106
Geoff - I know I shouldn't laugh, but I had to. The previous owner obviously wasn't one to be constrained by conventional thinking!Regards
Reply With Quote
  #6  
Old 5 Dec 2003
Registered Users
Veteran HUBBer
 
Join Date: Aug 2003
Location: Perth
Posts: 263
Chaps

Thanks for the replies, on inspection it seemed the manifold was OK but was still moving which points to the un vulcanised rubber from metal. Ive orderes another manifold and will adjust the mixture if it continues.
Reply With Quote
Reply


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

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


 
 

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:

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 23:58.