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Odd issue with fuel pump priming


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Today I went to ride home from work and the bike was really hard to start from cold.  It look around three attempts at the starter switch and it eventually started.  On getting the bike home I shut it off and re-started, all was fine.  But I noticed that there was no fuel pump priming noise.  I played around a bit with the ignition switch and I noticed sometimes the pump would prime and other times not. 

I eventually worked out that if the key was off and the switch was in the run position, the pump would prime as soon as I turned the key on every time.  I also worked out that if I turn the key to on and put the switch in the run position prior to the display initialising, the fuel pump would always prime.  Very strange problem.

I'ts not a show stopper, because I'll just make sure that the switch is in the run position prior to turning the key, so it should start fine tomorrow.  Has anyone experience this issue?  I hate to say it but it seems ECU related.

 

 

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Every time I turn the motor off, I use the red thumb button... I only hear the pump prime when I hit the starter button... 

I know some people just use the key to kill the motor which leaves the red thumb button in the ON state so as soon as you turn the key, the pump primes.  

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4 minutes ago, norcal616 said:

Every time I turn the motor off, I use the red thumb button... I only hear the pump prime when I hit the starter button... 

I know some people just use the key to kill the motor which leaves the red thumb button in the ON state so as soon as you turn the key, the pump primes.  

Yes, I usually shut the bike down by switching the red switch to stop and then I turn the key off.  And then I start by turning the key on first and then flicking the switch to start.  But I seem to remember the fuel pump used to prime every time the switch was put into run position with the key on.  It doesn't seem to do that now.

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I always regarded the red switch as an emergency kill switch and left it in the on position on all my bikes, never turned it off and always use the key.

Not sure if this is the "correct" procedure but never gave it much thought before.

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@TracerAU - If memory serves me correctly (that happens less often these days) this (occasional hard starting issue) was brought up in the past and at least in that instance it turned out that the battery voltage was ever so slightly low. 

I may be completely wrong here but at least its a quick, easy check.  

 

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4 hours ago, johnmark101 said:

I always regarded the red switch as an emergency kill switch and left it in the on position on all my bikes, never turned it off and always use the key.

Not sure if this is the "correct" procedure but never gave it much thought before.

If it was labeled "engine stop switch" would you use it? 

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+1 to @betoney. My battery voltage doesn't have to be very low at all to make it slow to start. 

Priming - as others have said. If I start with the red switch on or if I switch it before the Yamaha logo goes away you hear priming. If I wait until the logo goes away I never hear priming. 

OP is describing normal behavior. 

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5 hours ago, betoney said:

@TracerAU - If memory serves me correctly (that happens less often these days) this (occasional hard starting issue) was brought up in the past and at least in that instance it turned out that the battery voltage was ever so slightly low. 

I may be completely wrong here but at least its a quick, easy check.  

 

The first thing I checked when I got home was the battery.  It showed 13v with bike off.  And over 14v with bike running.  That seems ok to me.  Having said that it is an old battery, the build date of the bike in late 2016.  So I suspect the battery is that old too.

Edited by TracerAU
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4 hours ago, 1moreroad said:

+1 to @betoney. My battery voltage doesn't have to be very low at all to make it slow to start. 

Priming - as others have said. If I start with the red switch on or if I switch it before the Yamaha logo goes away you hear priming. If I wait until the logo goes away I never hear priming. 

OP is describing normal behavior. 

Ok, thanks for confirming.  I suspect in the past, I must have mostly flicked the switch to run prior to the logo display.  This behavior just seems odd to me, in that the fuel pump does not prime unless you switch it to run before the logo appears.

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1 hour ago, TracerAU said:

Ok, thanks for confirming.  I suspect in the past, I must have mostly flicked the switch to run prior to the logo display.  This behavior just seems odd to me, in that the fuel pump does not prime unless you switch it to run before the logo appears.

All Yamaha's new bikes work this way, it's normal.

The reason is that the kill switch disables all the engine functions, including the fuel pump.  This is a safety feature, and it makes sense when you look at it this way.

For some clarity, the "proper stop/start procedure" isn't important - it doesn't matter if you turn the bike off with the key, with the stop switch, or even with the kickstand switch.  They're all doing the same thing - well, the key does a bit more as it shuts down more, but the stop switch/kickstand switch/etc are all on the same circuit.  

With that said, as you noted if you use the stop switch to kill the bike, you'll lose fuel pump priming unless you switch it to run during "boot up", as the bike tries to prime the fuel system then - bumping the switch to "RUN" later doesn't help, because the bike has already gone past that stage of powering up.  This isn't harmful, but it does cause slower starts.  

This was from Yamaha directly, as I looked into it when I bought my MT07.  

I'd always previously used the kill switch on prior bikes, and as my MT07 was my first fuel injected bike, it was all new to me.  Couldn't figure out why it was so weirdly hard to start, being a brand new bike and all.  Ended up just training myself to turn it on/off with the key and leave the kill switch in "RUN" unless I had some specific reason to use it otherwise.  

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16 hours ago, norcal616 said:

Every time I turn the motor off, I use the red thumb button...

This ^^. No issues starting, as long as you allow the time to prime before ignition... and a safer way to shut off the bike. Good instinct to develop... and may save a few seconds in an emergency.

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  • 10 months later...
On 10/30/2019 at 4:36 PM, Wintersdark said:

All Yamaha's new bikes work this way, it's normal.

The reason is that the kill switch disables all the engine functions, including the fuel pump.  This is a safety feature, and it makes sense when you look at it this way.

For some clarity, the "proper stop/start procedure" isn't important - it doesn't matter if you turn the bike off with the key, with the stop switch, or even with the kickstand switch.  They're all doing the same thing - well, the key does a bit more as it shuts down more, but the stop switch/kickstand switch/etc are all on the same circuit.  

With that said, as you noted if you use the stop switch to kill the bike, you'll lose fuel pump priming unless you switch it to run during "boot up", as the bike tries to prime the fuel system then - bumping the switch to "RUN" later doesn't help, because the bike has already gone past that stage of powering up.  This isn't harmful, but it does cause slower starts.  

This was from Yamaha directly, as I looked into it when I bought my MT07.  

I'd always previously used the kill switch on prior bikes, and as my MT07 was my first fuel injected bike, it was all new to me.  Couldn't figure out why it was so weirdly hard to start, being a brand new bike and all.  Ended up just training myself to turn it on/off with the key and leave the kill switch in "RUN" unless I had some specific reason to use it otherwise.  

Thanks for edumecating me!... and leaving kill/start switch in run seems to have solved the issue. That said, is it 100% certain that battery voltage does not have anything to do with it? I am a severe creature of habit, for better or for worse, and in the first summer of owning my 2017 FJ-09 (picked it up in July 2018 with 1,000 miles on it) this issue only happened once, or twice at the most and I always waited for Yamaha display to run its ordeal before switching switch from off to run l, and never had any issues.
 

last summer I rode it to work all summer 4-5 days a week plus lot of other trips and never had this issue. The bike sat all winter (on trickle charger), but then got parked in the spring shortly after getting it  on the road due to needing a part from Japan.. that took two and a half months. Because of summer temps I never hooked up battery charger, but when I finally got my part it took a bit of effort getting it started the firsts few times, even after putting some time in the saddle charging battery. 
 

Now the battery seem to turn engine over ok, but when bike has been parked for 24 hours or more the prime don’t kick in when I go from stop to run. Once I’ve warmed it up and put in a few miles it is not an issue. Not suggesting you are wrong, but am I missing something?

Edited by fj09viking
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I've never use the kill switch to shut down on any street bike I have ever owned  . Never once have had a problem. Like was said if needed in an emergency ,use it otherwise leave it alone and eliminate the problems with priming !

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because of the awkward position of the key and how difficult it is to get my hand down that space while sitting on the bike, I turn my Tracer off with the kill switch. It's easier to get to the key when I am off the bike, so that is when I turn the ignition off, and lock the steering column.

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