Question about 1990 BMW K 100

2 Answers

Fuel leak Ive just bought bmw k100 and have a problem that i was hoping for some help with... I start her up and after about say ten seconds she cuts out and starts leaking fuel . It seems to be coming from just above the front of the battery bay, well back from the carbs, but its hard to tell. I cant see any fuel pipes around that area. Its a fair amount and it keeps leaking for a while after the stall then stops. I will add that i know nothing really about bikes. I also charged the flat battery with a car battery (car not running). Dont think this is important though?

Posted by on

2 Answers

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 6 Answers

Sounds like one or more of the floats in the carbs is not seating? No. Wrong. The K-100 is a fuel injected motorcycle.

Fuel is fed from the tank under pressure from an internal fuel pump-where it is fed from the left front of the tank to a fuel rail, the unused fuel is returned to the rear of the tank through a second hose. The first thing to check is that both clamps are snugged down, if the engine still stalls check the fuel rail pressure - the regulator may be out of whack allowing too much pressure to build up in the rail causing an excessively rich mixture.

I had the exact problem with my 88 K-100RT, the supply hose was found loose, snugging the hose down at the tank solved the problem. It also highlighted a condition; the hoses had deteriorated in the 20 years I had the bike, so I replaced both of them-none too soon either. This fuel system carries fuel under pressure, and although the leak seemed to cause the fuel pump to shut down after about 20 seconds - spraying fuel on a hot engine is a vary dangerous condition, to both you and and your motorcycle.

Posted on Jan 16, 2009

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 4 Answers

Sounds like one or more of the floats in the carbs is not seating, allowing the fuel to overflow the carbs. This would likely mean there is some trash or varnish in the float bowl. But, of course, there is a possibility that a fuel or vacuum line is leaking or has become disconnected. See, the fuel tap, also called the petcock, when it's set on "RUN" or "ON" only flows fuel when the motor is supplying vacuum to it. You may be able to switch it to "PRI" (Prime) and then find where it's leaking from. This way you don't even have to run the motor to get the fuel to flow. Good luck, keep us posted.

Posted on Nov 20, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Hi there, my BMW 1100 GS cuts out when the temp gauge stops working. She re-starts immediately and continues to run when no temp bars are showing. If and when they do re-appear, the bike huffs and puffs...


Hi, Peter the following applies to carbureted also fuel injected models and the usual suspects are:
1. Severely discharged or damaged battery, 9 volts or lower.
2. Failed alternator/generator and or voltage regulator.
3. Loose or corroded battery terminals and or cables especially the "NEGATIVE" cable, look for loose, corroded, or broken connectors inside the cable harness at "BOTH" ends.
4. Failed main circuit breaker or ignition switch, check for loose connections and continuity.
5. Failed system and or ignition relay, check for continuity.
6. Failed ignition coil, ignition/electronic module.
7. Failed CKP, CPS, CMP, MAP, TPS, or BAS sensor, corroded, loose or broken wire connector pins/sockets.
8. Throttle cables and or idle speed improperly adjusted hot idle speed should be 950 RPM to 1000 RPM.
9. Air/fuel mixture screw improperly adjusted.
10. Water or dirt in the fuel system, carburetor or filter.
11. Restricted, blocked or kinked fuel line.
12. Fuel tank empty.
13. Gas cap is not venting properly or fuel tank venting system blocked.
14. A failed fuel pump, pressure regulator and or fuel injectors.
15. Vacuum line from intake manifold to petcock broken, cracked, or not attached, carburetor vent line plugged.
16. Needle and seat stuck closed in the float bowl.
For more information about your issue, please visit the websites below. Good luck and have a nice day.
1999 2005 BMW R1100S Service Manual Moto Data Project
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1 http://www.k100.biz/pdf/FAQ/FAQ_K100_tips.pdf
Hints and advice for BMW bike motorcycle owners K1 K75 K100 K1100 bulb...

Feb 16, 2014 | BMW Motorcycles

1 Answer

Fuel pump on old K100 not getting power at all


Hi, Anonymous I am sorry you can't find the first and best tool you ever bought for your BMW but despair not for a mere $0 you can download another one. For more information about your issue, please visit the websites below. Good luck and have a nice day.
no power to fuel pump
Bad Fuel Pump BMW com
http://www.k100.biz/pdf/OFF/K100_K75_2V_eng.pdf
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1

Sep 02, 2013 | 2007 BMW R 1200 GS Adventure

1 Answer

Turn the key on did not hear the fuel pump come on.did this few times same answer.towed bike home.second day try to start it it firer right up.shut down and started it again 4xs it firer up. third da


Hi, Anonymous for this situation I would call my local dealer or reputable shop's service/parts department and inquire about any possible quick fix, answers, or parts inquiry. If necessary, transport your bike to the dealer or shop and have a professional technician take it for a test drive, if it is in running condition, and give you a written estimate of repairs and answer any specific questions you may have about your issue. For more information about your issue please visit the website below. Good luck and have a nice day.
http://www.k100.biz/pdf/OFF/K100_K75_2V_eng.pdf
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1 http://www.k100.biz/pdf/FAQ/FAQ_K100_tips.pdf
Tips Tricks
Hints and advice for BMW bike motorcycle owners K1 K75 K100 K1100 bulb...

Apr 04, 2013 | 1985 BMW K 100 RT

1 Answer

Does the fuel pump in my bmw k100 rt make noise when its on?


Hi, Anonymous for this situation I would call my local dealer or reputable shop's service/parts department and inquire about any possible quick fix, answers, or parts inquiry. If necessary, transport your bike to the dealer or shop and have a professional technician take it for a test drive, if it is in running condition, and give you a written estimate of repairs and answer any specific questions you may have about your issue. For more information about your issue please visit the website below. Good luck and have a nice day.
Aftermarket Fuel Pump BMW K75 K100 K1 K1100
http://www.k100-forum.com/t1982-whirring-and-metallic-clicking-noise-it-s-the-fuel-return-valve
http://www.k100.biz/pdf/OFF/K100_K75_2V_eng.pdf
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1

May 26, 2012 | 1985 BMW K 100 RT

1 Answer

How do you replace sparks plugs on bmw motorcicle k75s 1986 model


Hi, Elvirino I am sorry you can't find the first and best tool you ever bought for your BMW but despair not for a mere $0 you can download another one. For more information about your issue, please visit the websites below. Good luck and have a nice day.
BMW K75 replacing the sparkplugs
BMW Service K75 K100 Pre Buy Inspection
http://www.k100.biz/pdf/OFF/K100_K75_2V_eng.pdf
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
K75 Rider Manual English PDF Useful to K100 owners as well BMW K75 K100 K1...

Jun 30, 2011 | BMW K 75 S Motorcycles

1 Answer

Fuel leak


Sounds like one or more of the floats in the carbs is not seating, allowing the fuel to overflow the carbs. This would likely mean there is some trash or varnish in the float bowl. But, of course, there is a possibility that a fuel or vacuum line is leaking or has become disconnected. See, the fuel tap, also called the petcock, when it's set on RUN or ON only flows fuel when the motor is supplying vacuum to it. You may be able to switch it to PRI (Prime) and then find where it's leaking from. This way you don't even have to run the motor to get the fuel to flow. Good luck, keep us posted.

Nov 10, 2008 | 1994 Yamaha FZR 600

Not finding what you are looking for?
1990 BMW K 100 Logo

633 people viewed this question

Ask a Question

Usually answered in minutes!

Top BMW Experts

Arnie Burke
Arnie Burke

Level 3 Expert

4481 Answers

yadayada
yadayada

Level 3 Expert

61249 Answers

phil cuzins
phil cuzins

Level 2 Expert

79 Answers

Are you a BMW Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...