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 Josephine Flohr, Elephant at Camp, Namibia

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


Photo by Josephine Flohr,
Elephant at Camp, Namibia



Like Tree7Likes
  • 6 Post By martheijnens
  • 1 Post By dias

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 31 Dec 2013
Registered Users
Veteran HUBBer
 
Join Date: Aug 2002
Location: Utrecht, Netherlands
Posts: 147
F650 engine problem. Any advice?

Hi,

I ride a BMW f650 funduro, model 1999.

Currently I am in Kathmandu, Nepal, travelling from the Netherlands to Australia. The bike has problems which I describe below as accurate as possible.
1. The engine suddenly loses power, rpm falls back to stationary level but the engine stays running. This happens frequently but unpredictable. *
2. Opening the gas throttle has no effect on the rpm. Rpm stays on stationary level, engine gives some hard "bengs".
3. The only solution is to shut down and restart the engine. The problem seems to be solved but returns shortly after.
4. The problem as described appeared for the first time after a passed a major pothole. However I don't experience a relation between potholes/bumps and the occurance of the problem.
5. I had this problem leaving Sauraha (Chitwan NP) till the main road, a distance of about 6 km. The problem occurd maybe twenty times. However, being on the main road driving to Kathmandu the problem didn't occur. The next day, driving to workshop the problem was back again. So there seems to be some relation between the problem and the temperature of the engine.
6. I never had this problem before. *

Kathmandu Motorcycle Service Workshop has knowledge of European motorbikes. According to the mechanic the problem was probablt caused by failure of the carburators. So, they checked, cleaned and repaired the carburators. To no avail, *the problem persisted. Then we looked at the electric system, checked all wires and connections but found no visible damage. We measured the resistance of the sparks caps: 300 kilo ohm, which is much. So we replaced the caps with brandnew ones. The resistance of those caps was just 1 kilo ohm. I mad a testdrive again but to no avail, the problem was still there. After the testdrive we checked the resistance of the spark caps again. It was still 1 kilo ohm, so there was no electric pulse which damaged the caps. *

Has anybody a clue what causes this problem, what to do, how to go on? I am a bit desperate now!

Thanks, Mathew
__________________
Voorbij de horizon / beyond the horizon: www.wonderfultravels.nl
Reply With Quote
  #2  
Old 31 Dec 2013
Toyark's Avatar
-
Veteran HUBBer
 
Join Date: Apr 2006
Location: WWW
Posts: 2,341
Have you tried turning the throttle butterfly near the carb by hand?
It maybe that your throttle cable has popped out of the grip / snapped?

Also check that your spark plug isn't bridged (as in debris closed the gap of the electrode)

A bms-c reset might help too but it sounds like the throttle cable may well be (hopefully for you) the problem.
Reply With Quote
  #3  
Old 31 Dec 2013
*Touring Ted*'s Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2005
Location: Wirral, England.
Posts: 5,662
You need to go back to basics here... Unfortunately, I know SOD ALL about this model specifically.

Check everything methodically...

Fuel.... Check the filter. Are the vacuum pipes clear. Is it flowing freely.

Spark... Earth the plug to the frame and rev the engine.. Does it keep sparking ?? Is it a constant and rapid spark ?

Air filter... Clean ??

Carb ... All the vacuumn hoses intact ? Can you move the throttle by hand ??



The way you say that it comes and goes makes me think it's either electrical or a fuel delivery problem.
__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.
Reply With Quote
  #4  
Old 1 Jan 2014
mollydog's Avatar
R.I.P.
Veteran HUBBer
 
Join Date: Aug 2003
Location: california
Posts: 3,822
I'm guessing Fuel ...

I would check fuel flow out of the fuel tank. Also check for WATER in fuel tank. The petcock filters (they live inside fuel tank) may be clogged. easy to take out and clean!

Also, the Carb (or Carbs? Did the Funduro have ONE or TWO Carbs? :confused1: may have some sort of small inline filters at the fuel inlet point ... or? Sometimes are clogged. Go on line to BMW Funduro owner site and ask questions.

Drain float bowl(s). Remove pilot jet(s) and very carefully clean. have a very close look as the passages are TINY and may be clogged or have Varnish build up. Replace PILOT JET(s). Also pull Main Jet and any other jets and carefully clean ALL internal passages. Blow out with compressed air.
Do NOT lose any little parts. Go slow. THINK.

Make sure float needle is not clogged with debris (the float actuates the float needle and it then releases fuel into float bowl. Crap can get under the float needle contact point and clog. Float needle is a little pointed thing with rubber tip.

If you have a steady spark then must be fuel. Replace spark plugs if uncertain about them.

Good luck and thank goodness it's not fuel injected. Carb repair is cheap by comparison.
Reply With Quote
  #5  
Old 2 Jan 2014
colebatch's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Nov 2004
Location: London / Moscow
Posts: 1,913
Agree with Ted. Sounds like you are either not getting enough Fuel to engine or your spark is failing under load but idling ok.

Start with Fuel flow. Change the Fuel filter.

Then try Change the air filter

Try Change spark plug

Try n swap coil
Reply With Quote
  #6  
Old 2 Jan 2014
Registered Users
Veteran HUBBer
 
Join Date: Feb 2011
Location: NSW Australia
Posts: 139
Does your model have a mass air flow sensor? it could be sending a wrong signal to the bms. Some after market filters rub oil on them, not good, or the connection has jarred loose, it's on the "snorkel" 6 inches or so underneath prior to the air filter intake. Easy to pull out and clean, worth doing even if it's not your problem. Caution, use good electrical cleaner spray.
Reply With Quote
  #7  
Old 4 Jan 2014
Registered Users
New on the HUBB
 
Join Date: Jun 2013
Location: Australia
Posts: 1
Hi Mathew
Suggest you e-mail your BMW service company in the Netherlands and describe your problem as they may be able to give you options to work through. It sounds like a jet blockage from bad fuel, even though you have had them cleaned the work may not have been done correctly did the workshop in katmandu use plenty of carby cleaner? Good luck-Bruce
Reply With Quote
  #8  
Old 8 Jul 2020
Registered Users
New on the HUBB
 
Join Date: Jul 2020
Posts: 2
good morning i have the same problem with mine funduro f650 (1996), have you found the solution? thank you .
Reply With Quote
  #9  
Old 8 Jul 2020
Registered Users
Veteran HUBBer
 
Join Date: Apr 2008
Location: West Yorkshire UK
Posts: 1,785
The thread is 7 years old so if the OP didn't reply I doubt they will now.

All the suggestions above are valid.

I would add a compression test. These terrible old Rotax engines have weak head gaskets and automatic decompressors, so both a possible way to turn a 40 HP engine into a 10HP one. The decompressor thing in the head would make for an intermittent fault and be unfamiliar to Bullet mechanics in Kathmandu. Would tend to make a hissing noise though.

Also, try the Chain gang F650.com website, lots of info parked there in the FAQ section.

Andy
Reply With Quote
  #10  
Old 8 Jul 2020
Registered Users
Veteran HUBBer
 
Join Date: Aug 2002
Location: Utrecht, Netherlands
Posts: 147
Problem solved

The problem was caused by the rectifier. It died. If the rectifier doesn't function properly, the voltage goes up. Beyond 16,5 Volt, the electronic ignition device shuts down and the engine rotation falls back to stationary level. It was the first time I and the mechanics of Kathmandu Motorcycles Service faced this problem, so it took us a while to find out. The problem was probably caused by overheating of the rectifier. I bought a new rectifier and the mechanics improved the cooling by placing the rectifier on an aluminium plate.
__________________
Voorbij de horizon / beyond the horizon: www.wonderfultravels.nl
Reply With Quote
  #11  
Old 13 Jul 2020
Registered Users
New on the HUBB
 
Join Date: Jul 2020
Posts: 2
Thank you very much

thank you
Quote:
Originally Posted by Threewheelbonnie View Post
The thread is 7 years old so if the OP didn't reply I doubt they will now.

All the suggestions above are valid.

I would add a compression test. These terrible old Rotax engines have weak head gaskets and automatic decompressors, so both a possible way to turn a 40 HP engine into a 10HP one. The decompressor thing in the head would make for an intermittent fault and be unfamiliar to Bullet mechanics in Kathmandu. Would tend to make a hissing noise though.

Also, try the Chain gang F650.com website, lots of info parked there in the FAQ section.

Andy
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
Finally, a single cylinder adventure bike colebatch Which Bike? 305 27 Aug 2015 16:04
Advice needed in Mongolia: Transalp output shaft/ sprocket/ retainer problem, Urgent chris Honda Tech 19 20 Mar 2015 19:37
Stuck with engine problem in Mendoza, Argentina... Ideas? ljensen SOUTH AMERICA 16 13 Jan 2012 18:10
XT600E 2002 Engine Oil Trichelia Yamaha Tech 17 17 Nov 2011 14:25

 
 

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:

2025:

  • Queensland is back! Date TBC - May?

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 08:38.