|
12 Oct 2007
|
Registered Users
Veteran HUBBer
|
|
Join Date: Feb 2002
Posts: 212
|
|
Carb overflowing despite changing float valve
Hi all,
My 3AJ Tenere has an annoying habit of leaking petrol from the carb overflow hole in it's float chamber.
As far as I can tell it only happens when I turn the engine off, I have often looked when I have had to wait at junctions and never seen any sign of a leak.
Also, no amount of tapping the float chamber will stop it. I have inline fuel filters fitted and have changed the float valve and it's O-ring.
I guess float must be sticking on it's pivot pin but they seemed OK when I had the carb apart, and I am puzzled that I have never seen it happen when the bike is ticking over at junctions.
Are there any other possible explanations?
Could a faulty fuel pump somehow generate too much pressure so then it overcomes the float valve when the engine is turned off ?
Should the in-line fuel filters be able to empty when the engine is not running, and hence the fuel pump not operating?
Thanks for your thoughts
Mark
|
12 Oct 2007
|
Registered Users
Veteran HUBBer
|
|
Join Date: Mar 2007
Location: UK
Posts: 4,343
|
|
Just a thought
Hi,
Did you check the height of the float so that it is within tolerance?
That would account for why it does not overflow when the engine is running (taking fuel past the float) but it would when the float is closed.
Tapping the float chamber with the handle of a hammer used to fix my TT600R (same carb I guess) but not permanently; it does not have a fuel pump BTW, so no idea on that score!!
__________________
Dave
|
12 Oct 2007
|
Registered Users
Veteran HUBBer
|
|
Join Date: Jan 2001
Location: Stockholm
Posts: 651
|
|
Quote:
Originally Posted by Mark
Hi all,
My 3AJ Tenere has an annoying habit of leaking petrol from the carb overflow hole in it's float chamber.
As far as I can tell it only happens when I turn the engine off, I have often looked when I have had to wait at junctions and never seen any sign of a leak.
Also, no amount of tapping the float chamber will stop it. I have inline fuel filters fitted and have changed the float valve and it's O-ring.
** There might still be dirt keeping the needle open. To flush through, open fuel taps and drain screw at the bottom of the float chamber, and also tap tap. Let petrol flush through liberally.
I guess float must be sticking on it's pivot pin but they seemed OK when I had the carb apart, and I am puzzled that I have never seen it happen when the bike is ticking over at junctions.
** Never seen that, but could be. The explanation is that the vibes from the engine help the float to close. Float should be moving very smoothly.
Are there any other possible explanations?
** Bit of a wildcard, but your float might be leaking, meaning that it is heavier than designed and therefore closing at a higher gas level.
Could a faulty fuel pump somehow generate too much pressure so then it overcomes the float valve when the engine is turned off ?
** No. It depends on inlet duct pressure which is never high enough to counterbalance the closing force of the float.
Should the in-line fuel filters be able to empty when the engine is not running, and hence the fuel pump not operating?
** Normally yes, if the float opens the fuel should get through.
Thanks for your thoughts
Mark
|
Keep the faith ......
Auke
|
12 Oct 2007
|
Registered Users
HUBB regular
|
|
Join Date: Nov 2006
Location: Middletown, PA, USA
Posts: 52
|
|
One other thing I've heard of is to clean the float valve seat with a wooden golf tee before re-assembling the float valve and float. Sometimes the valve seat gets a buildup of varnish that keeps the valve from completely sealing.
|
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™ 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!
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.
|
|
|