V7 Stone Crank Position Sensors.

[SmithSwede]

I’ve now had two of these crank positions sensors fail on my 2013 V7 Stone.  The first was at 50,000 miles, the second at 90,000 miles.  I infer that these sensors only last 40-50K miles, at least in the Texas heat. 

Both failed without any prior symptoms.  Bike ran fine the day before, no missing, hesitation, same gas mileage, etc.  Then the bike simply would not start the next day. 

If this sensor fails, you get no spark and no gas.   But the yellow check engine lamp does not illuminate, and the starter motor cranks normally. 

You should get 640 ohms between the #2 and #3 pin.  On my second failed sensor, I was only getting 0.7 ohms. 

The sensor is very sensitive to the air gap.  If it is just the slightest bit too far out from the ring gear, you get no pulse and thus no gas and no spark.  So don’t add too much gasket sealer, make sure the O-ring is fully seated, and the two mounting screws are snug. 

You may want to remove the screws and wiggle the sensor up and down while cranking the bike to see if it will fire.   When I replaced my second failed sensor with a new part, the problem persisted.  I finally removed the O-ring and forcefully wiggled the sensor while cranking.   It fired up.  So it turns out the new sensor wanted to be even closer to the ring gear than the prior one.

The Guzzi part number is GU01721600.  Guzzi dealers sell it for $250 or so.  But the OEM part is actually Magneti Marelli SEN8E.  There are lots of cross referenced parts that are far cheaper, like $40 or less.  For example Facet 9.001.  Alfa Romeo 60512971.

[Vagrant]

Any chance the regulator is cooking it.

[SmithSwede]

That’s a good question.  I do have one of the “hot” regulators that runs the system at 15+ volts.   I’m told that how they speced these regulators and did not worry about it.

But maybe the sensor doesn’t like it.

[Kiwi_Roy]

They are a reluctance sensor, just a coil wound around a small magnet, I don't think there is any battery Voltage involved that type usually generates an AC signal.
As you say, the whole timing sequence depends on it so you are dead in the water without it.
Maybe something cracks as it's cooling down.

I know there are lots of cross references but I searched Vancouver looking for one, ended up buying a second hand from a breaker in Holland.

There is no excuse for Guzzi charging so much for a simple essential sensor.

I keep telling owners to monitor the Injection relay with a small LED
 

[Vagrant]

FYI, on the shall not be named site that was the one failure that keep showing up on the hot regulators. it went away with the change to a normal output. My 2015 V7 was hitting as high as 17.7 volts so I suspect I will be next.

[pyoungbl]

Do we have a cross reference section of Wild Guzzi?  This kind of information is mighty handy!

[antmanbee]

I have been tempted to buy a couple of these from china since they are so inexpensive. I still have a spare from a used engine I bought last summer. But these are cheap enough and small enough to stash one on your bike if you head out of town. I used to do that with points and condensers on my old T3, but I never needed them.
http://www.miparts.com/detail/rpm-sensor-engine-management_15598#.XOFD_8hKiUn

[Beowulf]

Really good info. Thank you for the parts numbers

I’ve now had two of these crank positions sensors fail on my 2013 V7 Stone.  The first was at 50,000 miles, the second at 90,000 miles.  I infer that these sensors only last 40-50K miles, at least in the Texas heat. 

Both failed without any prior symptoms.  Bike ran fine the day before, no missing, hesitation, same gas mileage, etc.  Then the bike simply would not start the next day. 

If this sensor fails, you get no spark and no gas.   But the yellow check engine lamp does not illuminate, and the starter motor cranks normally. 

You should get 640 ohms between the #2 and #3 pin.  On my second failed sensor, I was only getting 0.7 ohms. 

The sensor is very sensitive to the air gap.  If it is just the slightest bit too far out from the ring gear, you get no pulse and thus no gas and no spark.  So don’t add too much gasket sealer, make sure the O-ring is fully seated, and the two mounting screws are snug. 

You may want to remove the screws and wiggle the sensor up and down while cranking the bike to see if it will fire.   When I replaced my second failed sensor with a new part, the problem persisted.  I finally removed the O-ring and forcefully wiggled the sensor while cranking.   It fired up.  So it turns out the new sensor wanted to be even closer to the ring gear than the prior one.

The Guzzi part number is GU01721600.  Guzzi dealers sell it for $250 or so.  But the OEM part is actually Magnetti Marelli SEN8E.  There are lots of cross referenced parts that are far cheaper, like $40 or less.  For example Facet 9.001.  Alfa Romeo 60512971.