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In your first post you mention draining and cleaning the fuel tank but don't say if you put in fresh fuel. From my experience with my '06, after being winter stored with conditioned fuel it would be very hard to start first time in spring. So now I empty the tank, fill with fresh fuel and it fires right up. When cranking, do you hear it firing at all trying to start or is it completely dead? Also, have you checked compression and if the valves are in spec?
 

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Thanks fredsprint. The only way to eliminate this possibility would be to replace the sensor. It would be an expensive exercise to do this with any suspect part ( pump,injectors etc ) but that may be the price you have to pay for DIY. When I checked the sensor, I put my digital multimeter across the sensor (basically a induction coil of wire ) and it read 560ohms from memory which is what it is supposed to be from info picked up on the forums. I also put my meter on volts and swiped a spanner across the sensor and it registered the induced voltage milli volts. Cant remember what it was but it increased as the speed and number of passes increased. Not much else you can measure.?
You can plug an oscilloscope on the sensor while cranking to check the signal amplitude.
Alternatively you can plug it to your laptop microphone input using a PC free software. But you'll only be able to see the signal w/o a way to check the peak to peak amplitude unless you have a calibration signal handy.
I remember DEcosse made a checking apparatus made of two leds. One for the positive part of the wave and the other for the negative one.
 

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@Tartan Dave: did you perform the usual stepper/tps voltage checking
Thanks Fredsprint, but do you think it would start with gas and run perfectly when started if this was a problem?
Honestly no but anyway as it costs nothing it's worth checking. The failure linked to those sensors are always strange in the way they show up. It strongly depends on the starting algorithm.
 

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Discussion Starter #24
In your first post you mention draining and cleaning the fuel tank but don't say if you put in fresh fuel. From my experience with my '06, after being winter stored with conditioned fuel it would be very hard to start first time in spring. So now I empty the tank, fill with fresh fuel and it fires right up. When cranking, do you hear it firing at all trying to start or is it completely dead? Also, have you checked compression and if the valves are in spec?
Hi UlsterSpud,
Yes its fresh fuel. When cranking without the start gas there is no attempt to start. Using the start gas, it has a couple of fires which seem to create a snowball effect and then it starts. I took the plugs out to check for wetness after an attempted start, they were not wet, but not sure how wet you could expect them to be as most of the gas would be ejected. But, I noticed the plug gap was looking rather large and I thought I had solved the problem. They were set to 55 thou (approx 1.4mm ) so I reduced this to 35 thou.( .89mm ) .Did'nt work.!!
No , have not checked compression or valves, but the bike ran perfectly before the problem and runs perfectly now ( when started ). In fact my brother reckoned it was really pulling well, but that would probably be due to the large plug gap giving a lightning bolt spark, big flame front.
Dave
 

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Discussion Starter #25
@Tartan Dave: did you perform the usual stepper/tps voltage checking

Honestly no but anyway as it costs nothing it's worth checking. The failure linked to those sensors are always strange in the way they show up. It strongly depends on the starting algorithm.
Point noted fredsprint. I am having difficulty loading TuneEcu onto my laptop running Windows 10,( seems to be a problem locating the drivers ) the last time we ran it on my brothers which has Windows 7. May have to grab his laptop to use the software and do some more checks.
Dave
 

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Discussion Starter #27
Problem Solved ( But I don't understand why ).
My brother decided to take it to the Perth Triumph Dealership in Victoria Park. They checked it out on their diagnostic equip and said the problem was the Crankshaft Sensor. Apparently it was intermittent. Changed it and all is well.( The benefit of having parts available to swap).
I cant see why it should start with ether and run perfectly if this was the issue.? As I said I tested the sensor with a multi-meter (550ohms) and it produced some AC millivolts when cranking.? Also no error code on TuneEcu. Its working, so all is well.
Thanks to all the members who contributed with suggestions.
 

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Thanks for the follow up.
I had a car w/ a crankshaft senspr problem. It was difficult to start but once started it was OK. Until the day it completely refused to work at all. This was a known issue on that engine though. The ECU is able to "rebuilt" missing pulses while running, Plus the pulse strength depends on the rotation speed so smaller when starting.
For this reason some ECUs integrate a variable gain amplifier to input the same signal amplitude whatever the speed. Don't know whether the keihin includes that feature.
 

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Discussion Starter #29
Thanks for the follow up.
I had a car w/ a crankshaft senspr problem. It was difficult to start but once started it was OK. Until the day it completely refused to work at all. This was a known issue on that engine though. The ECU is able to "rebuilt" missing pulses while running, Plus the pulse strength depends on the rotation speed so smaller when starting.
For this reason some ECUs integrate a variable gain amplifier to input the same signal amplitude whatever the speed. Don't know whether the keihin includes that feature.
Thanks for that explanation fredsprint, it sounds like a plausible explanation. The bike actually did get to the point where it would not start at all, even with the ether so sounds a lot like your car issue.
 
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