![Reply](https://www.horizonsunlimited.com/hubb/images/buttons/reply.gif) |
![Old](https://www.horizonsunlimited.com/hubb/images/statusicon/post_old.gif)
19 Mar 2003
|
Registered Users
Veteran HUBBer
|
|
Join Date: Jan 2001
Location: Stockholm
Posts: 651
|
|
carburettor adjustment
I have been rebuilding my bike over the last months (a 3DS '88) and did following modifications:
1. Changed the carburettor (the Swiss 3DS with original jets and needles) for a 1VJ '87 carburettor with original jets and needles.
2. After 500 kms of running checked the plug and found it to be bright white, so I changed the jet of the primary carb from 145 to 150.
3. Installed stainless steel headers, with about 5 mm more in diameter.
The problem now is that the idle speed mixture screw screwn in totally gives the highest engine speed.
Float level is according to specs (25-27 mm). I have the standard air filter.
Idle running is not very neat; I have the feeling that the engine vibrating more than it did before I changed the carburettor.
Does anybody have an idea what should be done to get a) the idle adjustment as it should be and b) what could be done about the vibrations. I was thinking along the lines of changing the setting on the needles.
Any help much appreciated!
Auke
|
![Old](https://www.horizonsunlimited.com/hubb/images/statusicon/post_old.gif)
19 Mar 2003
|
Registered Users
Veteran HUBBer
|
|
Join Date: May 2001
Location: Zaandam, Holland
Posts: 119
|
|
Hi Auke,
Hmmm. The Swiss jetting/carburator is probably mainly based on higher altitude = less oxigen in the air so basicly smaller jets. Is that right?
If I remember right: the main jet only controles the mixture from half to full throttle. the needle controles it from 0 to 3/4 throttle, the idle jet when throttle is closed. Off course these controles overlap.
As far as I know the right procedure to 'read the plug' ('Coffee with milk' should be what you want) is the following:
To check if the main jet is correct: ride full throttle, if possibly up-slope or with head-wind, for a while and than cut the engine with the righthand switch (and use the clutch off course). Then check the plug (after you stopped :-)
Do the same with half throttle to check the needle position.
When you check the plug after the engine has idled you probably only check the idle adjustment. Which in your case could explain that indeed you cant adjust it right. The screw fully in and still not right probably means it gets still to much air ---> white plug.
So I wouldn't change the main jet until you are sure it to lean at full throttle.
Make sure the needle position is original 1VJ (needle up = clip down... can be confusing in the manual)
If it is try to lower the needle one position en check if you can get it idle properly. If not you may have to change the idle jet for a smaller one.
I'm not sure what you mean bij 'headers' but probaly the original (1VJ) size gives the least chances on problems.
Peter
|
![Old](https://www.horizonsunlimited.com/hubb/images/statusicon/post_old.gif)
19 Mar 2003
|
Registered Users
Veteran HUBBer
|
|
Join Date: Aug 2002
Location: Hendrik Ido Ambacht, Holland
Posts: 360
|
|
Sounds like your engine gets too much fuel @ idle somewhere. Maybe something wrong with the carb, especially the idle circuits.
I assume that when riding-in the fresh engine only the needle made your mixture.
Are you 100% sure the cam timing is correct?
What exhaust muffler are you using?
------------------
Fred, XTZ660, Holland.
__________________
Fred, XTZ660, Holland.
|
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
HTML code is Off
|
|
|
|
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.
"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.](/stuff/ripcord/ripcord-logo-250.jpg)
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!](/stuff/grahamfield/graham-field-2021-280.jpg)
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.
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.
|
|
|