Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Yamaha Tech
89 XT600 3EW spark issues / backfiring 89 XT600 3EW spark issues / backfiring
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 Giovanni Lamonica, Aralsk, Kazakhstan.

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


Photo by Giovanni Lamonica,
Aralsk, Kazakhstan.



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 19 Aug 2021
Registered Users
New on the HUBB
  
Join Date: Sep 2020
Posts: 4
89 XT600 3EW spark issues / backfiring
I've owned my XT600 for a while now and i've slowly been working my through its various issues, the one problem i have is backfiring / running hot and i'm hoping someone on here can help.
I've tested the stator coil, pulse coil, ignition coil, plug cap and plug - theyre all within tolerance.
I could be way off the mark here but when i kick the bike over with the plug resting against the block, the plug sparks continuously instead of one big fat spark at TDC.
Are there any other XT owners who could verify whether this is normal before i spend 2 arms and 3 legs on a new cdi?

I've made a youtube clip to demonstrate

https://youtube.com/shorts/qzoXS_Q7Sxg?feature=share

thanks in advance
Reply With Quote
  #2  
Old 19 Aug 2021
Registered Users
Veteran HUBBer
  
Join Date: Feb 2012
Location: Milan, Italy
Posts: 562
odd, can you confirm you have magneto/cdi iginition (and not TCI)? post a pic of youor igntion box if you dont know the difference...
Reply With Quote
  #3  
Old 20 Aug 2021
Registered Users
New on the HUBB
  
Join Date: Sep 2020
Posts: 4
Yes it’s cdi Turbo, see attached picture
Attached Thumbnails
89 XT600 3EW spark issues / backfiring-e682ff0e-a0fe-48ec-b5f9-f79aed0c971b.jpg  

Reply With Quote
  #4  
Old 20 Aug 2021
R.I.P. 25 November 2021
Veteran HUBBer
  
Join Date: Feb 2010
Posts: 688
Quote:
Originally Posted by turboguzzi View Post
odd, can you confirm you have magneto/cdi iginition (and not TCI)? post a pic of youor igntion box if you dont know the difference...
I see where you're going with that question, how is that possible with a capacitor discharge?

Mezo.
Reply With Quote
  #5  
Old 20 Aug 2021
Registered Users
HUBB regular
  
Join Date: Nov 2010
Posts: 66
89 XT600 3EW spark issues / backfiring
Hi,
I can't see if the spark is erratic or just fast. The picture needs to be steady for my tired old eyes

Don't know the code 3EW. '89 should be kick-start, but some early E bikes had both, and maybe CDIs. Why? determines speed constancy of kick start / electric start.

The CDI provides a spark on each revolution of the crank. It does look too fast. Maybe you can take a high speed video and then play it slowly :-)

I can't think of any reason how the CDI / trigger can generate an irregular spark. Also doubt the engine could run in any satisfactory way without a timed spark.

My '87 XT will pull well if i forget to open the fuel tap, until it dies, but will backfire on overrun very soon if fuel is low in carb. Lean mixture also a cause of running hot.

If i can't figure out the problem i treat the symptoms and see what happens. Try a richer mixture - raise the carb needle.

Be well'
p
Last edited by pete j; 20 Aug 2021 at 10:28. Reason: grammar
Reply With Quote
  #6  
Old 20 Aug 2021
Registered Users
Veteran HUBBer
  
Join Date: Feb 2012
Location: Milan, Italy
Posts: 562
like others, am not sure of what i see in that video, almost look like the extra sparks happen when you release the kick lever, not when you step on it.


cant think of any logical why a CDI would release extra sparks.

a TCI could in theory do it if there was some intermittent contact, thats why i asked



regardless, sounds to me lean mixture, not bad ignition.
does it start and idle ok?
was the bike running fine and then started to go bad or was like that since day one?

how is the color of your spark plug?
bike/problem history count when troubleshooting
Reply With Quote
  #7  
Old 22 Aug 2021
Registered Users
New on the HUBB
  
Join Date: Sep 2020
Posts: 4
Thanks for replying

The 3ew is the XT600 for the American market, it’s registered as an 89 but uses a lot of 84 parts, not much difference in spec just a supertrap end can and some extra oil breather feed in on the carb to appease US emissions.

As for the carb settings I’ve swapped the ydis carb for a new carb from a running bike so I know it shouldn’t be far away on settings.

I can’t start the bike to check the plug as it kicks back like a mule, although it does pop like it wants to start before it kicks back, the decompressor cable is set up to the specs in the manual (0.5mm), but I need to start the damn thing to fine tune the carb..

Hence why all of the above led me to question the sparking, I’d like to know from other XT owners if they’re bike has continuous sparks through one stroke rather than a fat spark at TDC?

In the meantime I’ll try bumping the bike to check the carb, thanks again..
Last edited by Mothball; 22 Aug 2021 at 09:49. Reason: Spelling
Reply With Quote
  #8  
Old 22 Aug 2021
Registered Users
Veteran HUBBer
  
Join Date: Feb 2012
Location: Milan, Italy
Posts: 562
like i said, when troubleshooting, every detail counts, it's like detective work to trace the killer....


you wrote "running hot" in your 1st post, so sounds like was it running before the problem? from your other comments sounds like it never run in your hands. whats the truth?



to answer your question: you should get one spark per engine revolution.

but you have to understand that its a very odd question.
a CDI needs power from the power coil to psark and that happens only once per revolution, in other words, technicaly it is not possible to have multiple sparks. or at least in my 40 years of experince never saw mutltiple sparks. but who knows, maybe your CDI is possesed



so the only way to see:
1. if you are more or less ok with spark timing

2. to check thats indeed only one spark


is to use a timing gun.



just throwing parts at it like carb, CDI, coil, pickup is going to be hit and miss as well as costly.
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
Jetting Issues with 43f XT600 Cheapxt Yamaha Tech 9 17 Sep 2019 17:39
Stiffer front springs for 1989 XT600 3EW Paddywagon Yamaha Tech 16 6 May 2019 19:58
XT600 cross model compatibility? 34L - 3EW ardo123 Yamaha Tech 2 24 May 2017 14:07
1998 Yamaha xt600 3tb stuttering issues Marcelo_xt600 Yamaha Tech 2 31 Dec 2015 20:21
1989 XT600 No Spark mackmanj Yamaha Tech 10 18 Dec 2012 15:30

 
 

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!

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 13:40.

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