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 30 Dec 2011
Registered Users
New on the HUBB
 
Join Date: Nov 2011
Location: vancouver bc canada
Posts: 18
XT550 HELP ! all back together but running poor

Yes ... unfortunately more help needed.

Finally got my xt all back together after installing a new top end. new piston and rings 1st os - rebore on the cyl - and recut valve and valve seats.

At first it started up just perfectly - second kick - idled smooth and ran really well.

I was taking it easy for the first run being cautious not to exert too much force on the new parts but making sure to run it up and down the rpms in low gears. after about 5 or 6 min or running i noticed it was backfiring a bit on decel, just a small pop once in a while.

I then put it in the garage for the night and the next day I took it out and it started up just fine - first kick this time and idled fine.

after it warmed up, I started to run the motor up a bit higher in the rps to about 3/4 throttle and after about 10 minutes of riding it started to backfire a lot more on decel and then it was running really rough at idle and it stalled out on me a couple of times.

it became difficult to start but did fire it up again and I managed to get it home by keeping the throttle on.

it is pulling fine and there are no flat spots but the backfiring is quite bad and the bike will not idle. it runs but skips, sputters and it is hard to tell but sort of sounds like it is popping out the exhaust and maybe a little gasp from the intake as well.

If the choke is open it will idle at about 2000 rpm but it falters, sputters and is generally unhappy.

I checked the plug and it looks perfect.

checked the valve clearance and the exhaust was still good, the intake had opened up a bit so I readjusted it. still no running improvement.

I have tried adjusting the air screw and it doesn't make any noticeable improvements.

I sprayed wd40 around the intake boots and noticed no increase in rpms, I check the exhaust manifold tightness and that all seems ok too, it doesn't appear to be leaking anywhere although I believe a leak would diagnose the running problem.

Also, while the bike was apart I did a very thorough carb clean so I am pretty sure that jets are ok. everything was spotless and cleaned in an ultra sonic bath - all jets removed and looked clean.

Any ideas? My next step is to pull the carb again and inspect the pilot jet and its circuit, pull the exhaust and check my seals. also will do a compression test and see where that is at - hope i didn't blow something up in there.

any other tests i can do to help diagnose the running issue?

Thanks in advance.

ps. the bottom end knock i was experiencing (http://www.horizonsunlimited.com/hub...-have-go-60120 ) was indeed solved by my new balancer parts - at least one good thing came of the rebuild so far.
Reply With Quote
  #2  
Old 30 Dec 2011
Registered Users
HUBB regular
 
Join Date: Sep 2011
Posts: 39
Possible fuel starvation if not drawing in air.
Reply With Quote
  #3  
Old 30 Dec 2011
oothef's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Feb 2010
Location: york
Posts: 265
Do you get a good flow if you pull the fuel line off the carb?
Float valve sticking, float level?
Breathers pinched or blocked?
Fuel quality?
Air filter?
As you say, crap found its way in to the carb?
__________________
Anything can happen in the next half hour
Reply With Quote
  #4  
Old 31 Dec 2011
Tenere99's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Jan 2008
Posts: 177
Valves?

You got the valve timing right? Easy to get one tooth out on the cam when re-building.
Reply With Quote
  #5  
Old 31 Dec 2011
Contributing Member
Veteran HUBBer
 
Join Date: Aug 2008
Location: Germany
Posts: 141
.....would start to check carb again:

floater level

needle valve (check underneath valve seat! Some carbs have a net filter there - but make sure anyway that fuel supply channel works fine)

.....and as I had to learn this the hard way also:

forgotten rags (intake)

Reply With Quote
  #6  
Old 31 Dec 2011
R.I.P. 25 November 2021
Veteran HUBBer
 
Join Date: Feb 2010
Posts: 688
Did you check/clean the filter on the float needle valve?

This is what it looks like on your 550.



Mezo.
Reply With Quote
  #7  
Old 3 Jan 2012
Registered Users
New on the HUBB
 
Join Date: Nov 2011
Location: vancouver bc canada
Posts: 18
"gotta check the jets" - quote from Two-Lane Blacktop

thanks guys, sometimes all it takes is a once over.
I pulled the air filter - gave it some gas, and whatever was stuck in there - probably something in the pilot circuit - came dislodged and now she runs just dandy. - i am running some seafoam through it to clear any left over debris but i'll pull the carb when i have a chance and give it another once over - for now it seems like whatever was clogging is now gone.

happy to have my baby back. now i just have to wait for better weather and then the hot springs are back within reach again.

thanks for all the help, glad there is all this support out there,

i'm still learning but hopefully i can pass on all things learned to others out there.

cheers
Reply With Quote
  #8  
Old 3 Jan 2012
oothef's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Feb 2010
Location: york
Posts: 265
Glad to hear.
What's seafoam?
I'd be tempted to pull the carb apart and give it a good dose of looking at, and carb cleaner.
__________________
Anything can happen in the next half hour
Reply With Quote
  #9  
Old 3 Jan 2012
Registered Users
Veteran HUBBer
 
Join Date: Mar 2011
Location: London
Posts: 105
Quote:
Originally Posted by oothef View Post
Glad to hear.
What's seafoam?
I'd be tempted to pull the carb apart and give it a good dose of looking at, and carb cleaner.

oothef Could have been one of these products

Sea Foam | Products

Bug cleaner! ?

Lets see that bike running to the
Reply With Quote
  #10  
Old 3 Jan 2012
oothef's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Feb 2010
Location: york
Posts: 265
Mmm, snake oil......
__________________
Anything can happen in the next half hour
Reply With Quote
  #11  
Old 12 Jan 2012
kentfallen's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Jan 2008
Location: Bexhill, East Sussex, England, UK
Posts: 673
XT550 Service Manual - Index of /josip/manuali/yamaha/xt550 (Long download be patient).
__________________
Triumph Bonneville 800 (2004), Yamaha XT600E (1999), Honda XBR500 (1986).

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tales from the Saddle klous-1 Ride Tales 88 4 Feb 2016 20:30
Sahara - XT500 - 1982 Chris Scott Ride Tales 17 28 Sep 2015 00:12
Cooking and braaaaaping around the world SBSRTW Ride Tales 35 8 Jan 2014 12:21
A Gringo in Colombia Ride4Adventure Ride Tales 13 20 Apr 2012 02:15
Khartoum to Ethiopia Birdy Ride Tales 2 26 Oct 2011 21:32

 
 

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 11:13.