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1150 Still Running Bad

D

dougjordan

New member
It started wile on freeway at 70mph, momentary loss of power, rolled on gas and it just bogged ,then ran normal. Then exit freeway slowing to stop 3000 rpm it died. The bike will only start with throttle half or more open. Then start to sound like it is running on one cylinder at 3000 rpm(#1) then die. Hooked up my gs911 no faults recorded . The o2 voltage looked arctic , unhooked sensor ran a little better but died at 1500 rpm still feels like on one cylinder below 2000 rpm. Made a test led setup to check HES, test good. Changed fuel filter,checked lines all good. New plugs. So now what? Bike is 2002 1150 gs with 45,000 miles.
 
Compression check my friend

You may have chunk-ed off a piece of an exhaust valve or got some carbon stuck in the valve seat. It's not uncommon for carbon build-up to break away on hard throttle and either burn a valve or stick it open. Do a compression check and if you have a real low value on one side plan on pulling both heads and refreshing them both. Low miles, probably well cared for and never rung out so it may be some carbon build-up has ruined your Spring vacation.
 
Agree with above post about checking compression. Your description of the symptoms and how they showed up just about exactly mimic what I experienced on my 01 R1100RT. I spent about 3 weeks checking everything else, fuel, spark, etc. and finally compression check showed loss of compression on one side. A small chunk of the exhaust valve was gone.
 
Compression check as others have suggested.
I had a burned an exhaust valve with exactly the same running symptoms
 

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Running bad

This is your friendly Redneck mechanic.

The first rule of Redneck BMW mechanics is to do your trouble shooting by checking the easiest and cheapest fixes to your problem.

1) check the right hand throttle body to see if the cable is properly seated.

2) open and close the throttle with the engine off to see if both throttle bodies are opening and closing.

3) pull the right and turn the engine over listening to the compression. Then have some one help you determine if the spark plug is firing

4) pull the left hand plug and compare the two plugs The tips should be the same color and the electrodes correctly gaped.

5) replace the right plug and turn the engine over listening to see if the compression is the same as the other cylinder. Have someone watch the spark plug to see if it is firing.

6) If either plug didn't fire trade the plugs from side to side and see if they are now firing. If the plug that didn't fire on one side doesn't fire on the other side change the plug. If the side where the plug didn't fire now with the good plug doesn't fire you have a problem with the spark plug wire or coil. Possibly just a bad connection

7) Before you get all ambitious check the spark plug wire. Look to see if the connection to the plug is in good shape and has a good contact with the wire. Then take the wire and bend it to see if it has a bad spot. If it is close to the plug, you may be able to fix it. BMW is mighty proud of those plug wires.

8) Raise the tank up and put a 2X4 under the back of it so you can get to the coils. Check to see if the wires are firmly in the coils, pull one plug wire out of the coil and see if the bike will start and run like it did before you started checking it out. If it does the clean the connection replace it and do the same to the opposite side. Now if the bike won't start on one side or the other you have figured out which side has the bad coil/spark plug wire. You can trace the spark plug wire on the non firing side to see where it has worn through the insulation. If you find it you can wrap plenty of electrical tape on it. Most of the time you can't see it, so if you find something insulated and with the bike running hold the wire away from anything it may contact. A real Redneck would trace down the plug wire with his fingers, I don't suggest doing it cause it may fry your pacemaker. If you found a bad wire and are on the road, and can't patch it most automotive stores will make you up a new wire. Its a lot of fun threading a new spark plug wire. A parts store will want it out so they can figure out the length so you need to attach a string/cable to it. Then when put the new wire in you can use it to pull it in.

9) Plug wires are OK, but one side still doesn't fire. The coil is bad. Replace.

10) Next thread if it still doesn't work we'll talk about fuel lines, filters, fuel pumps, etc
 
When you checked the fuel lines, did you check fuel pressure? Mr friends R1100S did all sorts of strange stuff with not idling and losing power when his formed "U" hose was starting to fail. We didn't see the cracks until we removed the hose and started bending it, but the fuel pressure test pointed the way. Obviously, others have had similar symptoms with a valve failure. I'd check fuel pressure & flow along with compression in whichever order is most convenient. Hopefully one of them will point the way. Good Luck.
 
GSAddict said:
Interference engine, all hell would break loose.
His engine runs at higher rpm.
Click to expand...
One of my R1150RT cam chains failed at speed on the highway. The bike stalled but later restarted and ran on one cylinder. No damage was done to valves (found to be all closed) or piston, perhaps that was luck.
It's easy to inspect the cam chain via the cam sprocket access cover, no harm in checking.

Yes, if engine runs better at higher rpm that correlates more with something else, like erratic TB butterfly valve.

Another obvious and simple test is to see which cylinder remains cold after engine starts.
 
I like that, keep it simple.

Voni said:
I think it may be no worse than water in the gas.
Click to expand...

Simple problems can result in overly complicated diagnosis and repairs that aren't really needed.

All the other suggestions have merit once you ruled out the simple things. I would even suggest checking all your ground connections as well.
 
Compression Test Done

dougjordan said:
It started wile on freeway at 70mph, momentary loss of power, rolled on gas and it just bogged ,then ran normal. Then exit freeway slowing to stop 3000 rpm it died. The bike will only start with throttle half or more open. Then start to sound like it is running on one cylinder at 3000 rpm(#1) then die. Hooked up my gs911 no faults recorded . The o2 voltage looked arctic , unhooked sensor ran a little better but died at 1500 rpm still feels like on one cylinder below 2000 rpm. Made a test led setup to check HES, test good. Changed fuel filter,checked lines all good. New plugs. So now what? Bike is 2002 1150 gs with 45,000 miles.
Click to expand...
No compression in #1cylinder and 125lb in#2, cold engine ,no air filter 125 should come up when hot.
 
dougjordan said:
No compression in #1cylinder and 125lb in#2, cold engine ,no air filter 125 should come up when hot.
Click to expand...

125 cold is low for #2, did u do the test with the throttle wide open?

No C in #1 is a burned valve

High carbon buildup from oil consumption contributes to this issue.
A chunk of carbon breaks off and gets lodged under the valve holding it open.
It takes milliseconds for the gases to burn the valve.

What was the consumption on your machine?
When you pull the heads post the amount of carbon in the chamber & piston

If high, you should consider re-ringing if you are going to keep the bike.
A fresh set of rings, deglazed cylinders and an aggressive breakin in the first 50 mile will ensure a low oil consumption boxer.
Many 1150's were oil slurpers as they were broken in gently, including mine (purchased @ 9 months old)
I did the above, started it after the repair, rode immediately until 4 bars and then rode it like was stolen for 50 miles.
Over 100,000 miles later she still does not use more than 100ml/1000km(600m)
 
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