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Selden

F700GS Engine Hesitation

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Selden

2014 F700GS, ~10500 miles, no mods other than an aftermarket muffler ~3000 miles ago.

 

During a ~100 mile ride today,  2 miles after stopping for lunch in Blairsville, the engine hiccuped, something it has never, ever done in ~6000 miles, including the ride home from where I bought it in Tennessee with 95° temperatures.

 

A few miles later more hiccups, including one where it lost power for about 1 second. I took the Richard Russell Scenic Highway to Cleveland with only a few hiccups, but it was bucking like a bronc the last mile to Ingles. I bought a 5.5 oz bottle of STP injector cleaner at Ingles, and poured half of it into the tank. I had filled the tank at the same Ingles yesterday, and there had been not hesitation for the first ~90 miles after that fill.

 

From there, smooth sailing for ~12 miles, when it hesitated again. I decided to press on, because the problem was intermittent, and we had only ~12 miles to home. It cut out a few more times, including another one that lasted ~1 second, but we got home uneventfully.

 

So, I still haven't decided if it's fuel related, or if one of the stick coils (I assume that's what this engine uses, although I have never looked) is going bad. I am inclined to watch and wait. If it's fuel, the injector cleaner and a few tanks of gas should clear the problem. Since the problem started only a few miles south of Blairsville, I'm inclined to think it's NOT heat related. I took off the seat and washed the bike last weekend, but have done absolutely nothing else since yesterday's fill, so a wet component seems very unlikely. If I get stranded in the Dahlonega area, my wife can always come pick me up.

 

I searched the F-bike list, and come up with this somewhat similar description, which is notable for good details (note that my instrument panel has not thrown any fault codes, nor has the engine actually stopped):

 
On my trip back from Las Vegas last Friday I had a weird experience. It occurred about an hour after a fill up (Chevron) at Barstow when I stopped at San Bernardino due to traffic (thought it was a good time to stop and grab something to eat). Basically when I pulled in the clutch to stop the motor died. Starting it back up, the motor was rough and would barely run. I managed to start it by keeping the throttle on and pulled into Popeyes. When I went to leave though it immediately popped a fault code so I turned it off and restarted it. It was still rough. Almost like it was running on one cylinder, but once I got it on the highway all the issues went away.
 
The issue did not reoccur in traffic. Nor did it occur when I arrived home an hour later. I checked the fault codes with my GS-911 (motor not running) and it stated:
 
Fault Codes 1
 
10311 Throttle Position potentiometer faulty
Currently present NO
Symptom No signal or value
Engine warning light (MIL) NO
Frequency count 2
Logistic(Healing) count 40
 
Fault Code History -
 
Record number 0
Odometer 13427.2 mls
Throttle valve potentiometer voltage 4.88 V
Engine speed 4760.0 rpm
Vehicle speed 1118.5 mls/h
Adapted voltage at closed throttle valve 0.66 V
Record number 1
Odometer 13427.2 mls
Throttle valve potentiometer voltage 4.88 V
Engine speed 4520.0 rpm
Vehicle speed 1118.5 mls/h
Adapted voltage at closed throttle valve 0.66 V
 
Response: The TPS is simply a variable resistor - failure mode is usually associated with wear on the resistor track coating causing dead spots, or by the worn off carbon causing noise. Given your low odometer reading, and the fact that the recorded symptom is 'No signal or value', I'd suggest it is more likely a problem with the connection/wiring between the TPS and the BMS-K. It would be worth simply disconnecting the TPS at its connector and checking/cleaning the terminals, and similarly the connection to the BMS-K.
 
Then hook up the GS-911 again and use it to reset the TPS adaptive values (from my experience, I haven't been able to show that the non-GS911 procedure often quoted on this forum works - but it might). After your cleaning routine, maybe you can check the % throttle reading at zero and at fully open, go through the 'manual' reset procedure, and then see if the % readings change (unless they were 0% and 100% at the start, then there's no change to the adaptive values required anyway).
 

I don 't have a GS-911, but  based on this advice, I plan to pull the seat tomorrow morning when it's cool, then unplug, clean, and re-connect anything that has a plug. Then watch and wait.

 

Any other thoughts?

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Marty Hill

Good luck finding and fixing.  PS, let me know what you find since I have the same bike.

Marty

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dirtrider
40 minutes ago, Selden said:

2014 F700GS, ~10500 miles, no mods other than an aftermarket muffler ~3000 miles ago.

 

During a ~100 mile ride today,  2 miles after stopping for lunch, the engine hiccuped, something it has never, ever done in ~6000 miles, including the ride home from where I bought it in Tennessee with 95° temperatures.

 

A few miles later more hiccups, including one where it lost power for about 1 second. I took the Richard Russell Scenic Highway to Cleveland with only a few hiccups, but it was bucking like a bronc the last mile to Ingles. I bought a 5.5 oz bottle of STP injector cleaner at Ingles, and poured half of it into the tank. I had filled the tank at the same Ingles yesterday, and there had been not hesitation for the first ~90 miles after that fill.

 

From there, smooth sailing for ~12 miles, when it hesitated again. I decided to press on, because the problem was intermittent, and we had only ~12 miles to home. It cut out a few more times, including another one that lasted ~1 second, but we got home uneventfully.

 

So, I still haven't decided if it's fuel related, or if one of the stick coils (I assume that's what this engine uses, although I have never looked) is going bad. I am inclined to watch and wait. If it's fuel, the injector cleaner and a few tanks of gas should clear the problem. Since the problem started only ~4 miles from Dan's, I'm inclined to think it's NOT heat related. I took off the seat and washed the bike last weekend, but have done absolutely nothing else since yesterday's fill, so a wet component seems very unlikely. If I get stranded in the Dahlonega area, my wife can always come pick me up.

 

I searched the F-bike list, and come up with this somewhat similar description, which is notable for good details (note that my instrument panel has not thrown any fault codes, nor has the engine actually stopped):

 
On my trip back from Las Vegas last Friday I had a weird experience. It occurred about an hour after a fill up (Chevron) at Barstow when I stopped at San Bernardino due to traffic (thought it was a good time to stop and grab something to eat). Basically when I pulled in the clutch to stop the motor died. Starting it back up, the motor was rough and would barely run. I managed to start it by keeping the throttle on and pulled into Popeyes. When I went to leave though it immediately popped a fault code so I turned it off and restarted it. It was still rough. Almost like it was running on one cylinder, but once I got it on the highway all the issues went away.
 
The issue did not reoccur in traffic. Nor did it occur when I arrived home an hour later. I checked the fault codes with my GS-911 (motor not running) and it stated:
 
Fault Codes 1
 
10311 Throttle Position potentiometer faulty
Currently present NO
Symptom No signal or value
Engine warning light (MIL) NO
Frequency count 2
Logistic(Healing) count 40
 
Fault Code History -
 
Record number 0
Odometer 13427.2 mls
Throttle valve potentiometer voltage 4.88 V
Engine speed 4760.0 rpm
Vehicle speed 1118.5 mls/h
Adapted voltage at closed throttle valve 0.66 V
Record number 1
Odometer 13427.2 mls
Throttle valve potentiometer voltage 4.88 V
Engine speed 4520.0 rpm
Vehicle speed 1118.5 mls/h
Adapted voltage at closed throttle valve 0.66 V
 
Response: The TPS is simply a variable resistor - failure mode is usually associated with wear on the resistor track coating causing dead spots, or by the worn off carbon causing noise. Given your low odometer reading, and the fact that the recorded symptom is 'No signal or value', I'd suggest it is more likely a problem with the connection/wiring between the TPS and the BMS-K. It would be worth simply disconnecting the TPS at its connector and checking/cleaning the terminals, and similarly the connection to the BMS-K.
 
Then hook up the GS-911 again and use it to reset the TPS adaptive values (from my experience, I haven't been able to show that the non-GS911 procedure often quoted on this forum works - but it might). After your cleaning routine, maybe you can check the % throttle reading at zero and at fully open, go through the 'manual' reset procedure, and then see if the % readings change (unless they were 0% and 100% at the start, then there's no change to the adaptive values required anyway).
 

I don 't have a GS-911, but  based on this advice, I plan to pull the seat tomorrow morning when it's cool, then unplug, clean, and re-connect anything that has a plug. Then watch and wait.

 

Any other thoughts?

 

Afternoon Selden

 

Is this the first time out this year or have you been riding  it continually? 

 

If it was in storage then possibly a fuel pump issue, BMW didn't anodize the alloy fuel pumps on the 700/800 bikes in your model  range so the pump can corrode from alcohol in the fuel then internals start to seize up. Kind of a long shot if it started OK after storage (if you even stored it).

 

The other possibility is that there was a side stand switch recall on some of the 2012-2013 700/800 bikes, I know your bike is 2014 but that recall went all the way up through 700 bikes built up to   Sep 19, 2013. Usually a side stand switch issue on the 700 bikes causes a no start but at times it can also cause an engine cut out.

 

Was your tachometer operating OK during the engine mis-fire? This can help us know what direction to look in.

 

But up front your problem more points to a water-in-the fuel issue so definitely eliminate that possibility before chasing other things. 

 

 

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Selden

Thanks, DR. I was hoping you would chime in. The GS has been ridden continuously (or at least to the extent possible, given the wet winter we have had). During winter, when it is ridden less, I always put a small amount of STA-BIL in each tank, as well as in the 2-gallon jug that I use primarily to refuel the XT225. 

 

I did not notice the tach behaving erratically.

 

Last night I pulled the Motronic and disconnected both connectors — clever, and very positive latching system, once I figured it out. Sprayed with DeOxit, then plugged/unplugged a few times. Looking under the seat, it seems extremely unlikely that the weight of a ~130-pound passenger (including gear) would put any stress on the Motronic connectors.

 

This morning I rode into town to pick up a bottle of HEET fuel dryer, and a few supplies. Not surprisingly on two 7-mile trips between 58° and 68° it behaved perfectly. So, it's watch and wait time. 

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