Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > BMW Tech
BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only.
Photo by Michael Jordan, enjoying a meal at sunset, Zangskar Valley, India

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

Photo by Michael Jordan
enjoying a meal at sunset,
Zangskar Valley, India

LinkBack Thread Tools Display Modes
Old 19 Jun 2012
Registered Users
New on the HUBB
Join Date: Jun 2012
Posts: 1
Please help F650GS overheating

My F650gs '04 first overheated when slowing after a long high speed run. I topped up the coolant resevoir plus radiator (and bled the system using the bleed nipple on the cylinder head). No improvement. So I removed the thermostat and checked it - it was sticking 'open' rather than closed. I decided to run the bike without a thermostat (whilst waiting for a replacement) assuming this would mean the bike was cooled from start up. The bike is still overheating. There is no weeping from the water pump drain hole and the pipe leading from it up to the radiator is getting hot so I think I am right in assuming theat the coolant is circulating. I have reset the ECU by disconnecting it for 15 minutes. None of this has worked - the bike still overheats. It is not a sensor problem - I know this because if I continue to run the bike when the warning light is on the pressure 'burps' back to the resevoir and vents through the pin hole in the top of the filler cap. I cannot fathom what is happening. If there are any sympathetic tekkies out there please help - I am at the end of my tether!

Reply With Quote
Old 19 Jun 2012
Registered Users
HUBB regular
Join Date: May 2012
Posts: 65
is your fan working?
Reply With Quote
Old 19 Jun 2012
colebatch's Avatar
Registered Users
Veteran HUBBer
Join Date: Nov 2004
Location: London / Moscow
Posts: 1,913
is your radiator blocked with mud?
Reply With Quote
Old 19 Jun 2012
Registered Users
New on the HUBB
Join Date: May 2009
Location: cumbria uk
Posts: 11
Stripped the water pump gears a possibility.
Reply With Quote
Old 19 Jun 2012
Registered Users
New on the HUBB
Join Date: May 2009
Location: cumbria uk
Posts: 11
I forgot to add should you have a problem obtaining a replacement thermostat.
Take your old one along to a car parts shop as its my understanding the thermostat from a VW Lupo or pre 2002 Golf will fit.

Good luck
Reply With Quote
Old 20 Jun 2012
Registered Users
Veteran HUBBer
Join Date: Dec 2006
Location: Moscow
Posts: 1,117
Failing Colebatch's suggestion of checking for a blocked rad (which he know all about from my Dakar!) I would follow cy01's suggestion of water pump area.

Although not weeping through the drain hole beneath (but you are not experiencing fluid loss are you?) that does not mean the shaft or impeller is turning OK.

A new shaft pump kit is about £25 from Motorworks and the two gear wheels about the same. It is a straightforward hour or so to replace - except on a Dakar where the oil pipe is a real bitch. Be prepared with a new clutch cover gasket - or the means to make one.
Reply With Quote
Old 20 Jun 2012
Lifetime Member
Veteran HUBBer
Join Date: Sep 2009
Location: Australia
Posts: 365
Assuming you have checked the radiator is clear my thoughts of things in priority order to check before you assume a mechanical failure of the pump or other major problem:

(i) Check cooling fan is coming on - fan or its sensor could have failed.
(ii) Check radiator cap - a failing (hard or cracked) seal will stop system pressurising as it is suppossed to do and cause overheating. Best check is often replacement - they don't last forever.
(iii) In some car engines removing the thermostat can cause overheating - this is because it allows an accelerated flow rate through the radiator which gives insufficient time for the water to be cooled. So fit the new thermostat and check if that applies here.
(iv) Anti freeze is also an anti-boil fluid as it raises the boiling point of the coolant. If the mixture has become too weak due to periodic topping up with plain water (or from not changing it for many years) you can get over heating symptons.
(v) Similarly if the engine has been run for awhile without enough anti-freeze in the mixture - scale and corrosion in the passageways of the engine can be restricting flow. Descaling and flushing out engine and radiator with lots of clean water may then help.

If all of the above don't solve it then:
- could be failed water pump.
- could be a blown head gasket.
- could be an ignition timing issue ( but you'll usually notice lots of other symptons such as lack of power first).

Try the simple ones first - in my experience 90% of the time its one of those. Good luck.

finally back on the road again

Reply With Quote

f650gs, overheating

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
Wanted bmw f650gs high seat. Gary117 TRAVEL Equipment for Sale / Wanted 0 14 Jan 2012 17:39
BMW F650GS problems in Nicaragua-need new clutch Smokechaser Central America and Mexico 4 11 Jan 2012 04:13
2001 F650GS Broken Down in Quito Jordan SOUTH AMERICA 8 21 Dec 2011 12:03
2001 F650GS Broken Down in Quito Jordan BMW Tech 3 21 Dec 2011 00:22



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.



  • Queensland is back! May 2-4 2025!

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 09:53.