That's almost a how longs is a piece of string question.  Some can fail in a matter of years others still working fine and everything in between.  As a general rule it's more mileage related than time.

As there's only two coils with 2 HT leads it would be 2 cylinders not firing, not just one, if you had a coil issue.

If you've had issues which prompted you to remove the carbs and clean he pilot circuit? Chances are it's still that, that's the issue.  Does the cylinder fire and run/rev above 4k?  If so it's not the HT circuit, it's the carb.

I got a knock on the door last night. My neighbour with a package!  They have has it since Tuesday and FedEx did not advise where they had delivered it or even that they were delivering on what day. A really bad service.

The ignition switch is an OEM unit in Yamaha box. All looks legit. I’d read there were two plugs, one had two wires and one had 5 wires!! The new unit has two plugs, one with two wires and one with three wires. I’ve taken the tank off today to check and it is the correct number of wires.

Just got to arrange fitting now.

Thanks to everyone who has contributed to this thread.

Check this out , I had a similar issue and this is what I did.   https://foc-u.co.uk/index.php?action=downloads;sa=downfile&id=67

hi there , i have a 2001 fzs600.  this fuel gauge has played up before but was cured simply by disconnecting fuel reader connection block spraying wD 40 into it and ridding the furring ( ver de gris ) off the connections and it was working perfectly again.  this time possibly coincidentally as a result of needing to temporarily disconnect the battery to do  a different job entirely , found the fuel gauge which worked before was now not working properly , that is to say not working as it should !  i have checked for the same issue as first time , all clean still and no reason to suspect similar reason as before .
the tank is about 70% full yet the fuel gauge will slowly climb up to the first mark above empty and no more , the needle drops back where it should  when ign off, so it is operating but not normally ( if were allowed to use such a word these days  [size=78%])    [/size]

what could be the reasons and solutions ? how would i verify the faulty items ?

in the interim two questions,

although the gauge wont go any higher than first mark , would it react normally when fuel is lower than where its reading right now?

does the fuel warning light depend on working fuel gauge?  is it linked or independent to the fuel gauge , in other words can i rely on the fuel warning light despite faulty gauge ?

just thought of a third question now , when fuel warning light does come on , how much fuel do you have left ?  obviously fuel up immediately but what does the fuel warning light represent in mileage terms ?


thanks anyone who responds   

I paid by PayPal so I’ll go through them. I think I need to give them a couple of days to respond. I wrote to both parties yesterday.

The switch you suggested turned out to be the wrong one, two plugs with two wires each. I couldn’t get to the bottom of what ‘stuff to turn’ meant and it was an uphill struggle trying to find out if it was any better than mine. I wasted 5 days writing and responding and getting the same replies. I just gave up.