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Strange starting issue

168K views 491 replies 110 participants last post by  S.Ga.Rider 
#1 ·
I have a 2012 Thruxton, about a month old now that every once in awhile only turns over a split second when pressing the start button. Pressing it again causes it to turn over another split second but still fail to start. If I press and hold the start button, it will turn over a split second and then after a very predictable amount of time (about 2 s) turn over and completely start.

I'd diagnose it as a glitchy sensor, button contacts, or relay if it weren't for the fact that pushing the button always causes it to turn over, if only for a split second. I'd diagnose it as a dying battery if it weren't for the fact the bike is a month old and ridden for 30 minutes at a time twice a day. So, I'm a bit confused and wondering if there is some sort of ECU involvement on the EFI models starting circuit? Perhaps a voltage brownout when initially engaging the starter?
 
#4 ·
Are you using the cold start pull-out "choke" when trying to start the bike?

According to my hand book this pull-out control should be used every time you start the bike; Position one for warm starts and warm weather; position two for colder weather.

I get that split second thing occasionally on my 2010 T100 if I don't use the "choke", but never get it if I do use the choke.

Dave
 
#5 ·
No Spark

Being a electrical technician, it sounds like a poor switch contact. Things to look for 1: check the bike stand switch - if its up position is not correct that switch will cut out the starting due to vibration from starting. 2: check the clutch switch adjustment. your really looking for poor switch contact or a loose wire where it connects to a switch. Also check the starter motor relay connections and the battery connection. Poor battery connection causes voltage drop when cranking which will drop out the starter relay. Test cranking volts - should be above 9volts when cranking.
Good luck.
 
#94 ·
Electric contacts

it sounds like a poor switch contact.
I have had the same thing on mine, bike had been washed or stood, and the starter contact had some surface rust. but with previous triumphs i would also agree about checking the return switch on the stand as that's cropped up a few times.

given that the thruxton has the 'safety' feature of light on during start up, battery strength is a big issue. i swapped to a better one and its improved significantly. but at some point i'll get an improvised switch on to control that.
 
#6 ·
For what it's worth: I've been having this problem with one of my other bikes (not a Triumph) and it happened to be the battery that did not produce enough oumph.
I know your bike is new and all, but for how long has it been standing at the dealer's before you bought it? Maybe your battery is in a worse condition than you think...
 
#8 ·
That thread was a good read, thanks. I just checked my battery connection and all is good there. I'm still a little skeptical of it being the clutch switch simply because it always turns over a split second AND turns over again precisely 3 seconds later if I keep my finger on the start button. That would make sense if the battery voltage took a dive from the initial surge current of the starter solenoid/motor enough to engage the ECU low voltage interlock mid crank. The battery then recovers voltage after a few seconds with the headlight off due to the start button being depressed and resumes cranking as the low voltage interlock releases.

Im betting it's combination of the low voltage interlock being too sensitive and this battery being slightly weak.
 
#10 ·
I'm having the exact same thing on my 2012 T100 (has about 1700 miles). After reading the other thread on this, I first checked battery cable connections (they seemed tight, but tightened them a bit more). That didn't fix it, so I did the mod where you remove the clutch switch and cut off the plunger portion of it, so it effectively always leaves the clutch switch contacts closed. This way, you don't have to pull in the clutch to start. Well, it's still showing the same symptoms every now & then. I'm thinking that it's either marginal contact in the clutch safety switch contacts, or what you say about the ECU low voltage interlock. I may try soldering the wires at the clutch switch closed first, which would completely bypass the switch. More to come.....
 
#11 ·
Hook a multimeter up to your batt when you do this intermitten crank. See if when the first bump the battery drops down enough to stop it from cranking.

If when you do this you cannot see it by batt voltage alone, hook a test light to the stater solenoid S wire and see if the light goes out for three seconds interupting the magnetization of the relay. Back trace it from there.

Might just need a wire pushed in somewhere.
 
#13 ·
Well, I did measure the voltage at the battery terminals. Just before cranking over, it measured about 12.7 V, and as it was cranking it went to about 10.5 V. So it seems like the voltage drop wasn't too bad. I also tried what jesseoff suggested, and just kept the starter button pressed in, and when doing that, after it cranks for a split second and then stops, by keeping the starter button held in, maybe a second or so later it cranks again, and then starts up! Definitely strange.... doesn't seem to be a "bad" or dirty connection at the starter button, since I was holding my thumb really still on the starter, and I've already disabled the clutch safety switch. Any more ideas of what could be causing this???
 
#14 ·
I'm not sure the multimeter is going to catch just how instantaneously low that first half crank gets. Likely the ECU is measuring voltage probably 100-1000 times per second and if any one of those readings is below some magic threshold it disables the starter.

On electrical motors such as the starter, the biggest current draw is right before it starts moving. Maybe the random cylinder position from the last shut down makes that first crank compression stroke draw too much current from the little battery?

Since it happens so randomly, I'm not keen on riding all the way to the dealer, waiting a day for them to look at it only for them to say they couldn't reproduce the problem.
 
#16 ·
Now I'm wondering if it could be a marginal or weak battery, for the following reason: Last night, I wanted to adjust the angle of the headlight, so after doing that I was riding around the neighborhood with the high beam on for maybe 10 min (with slow engine revs, which I assume means not much charging to the battery, with a heavier than normal electrical load).
Then, this AM, when I tried to start it up to go to work, it cut out the worst it's ever done. It took maybe 7 or 8 tries before it finally would start! I was just holding the starter button in, and it would crank for a split second, pause, then do it again until I finally had to release the starter button for a few seconds, then it started on the next try. You would think that since the bike is brand new the battery would be good, but I guess it's possible to have a "bad" battery. I can't remember from looking at it, are these batteries the kind that you have to add distilled water? Should I check that?
 
#17 ·
These bikes seem to be real sensitive to battery issues they seem to like everything they can get from them it will be interesting to hear the solutions to you problems so we can learn more.
Cheers Klem
 
#18 ·
#22 ·
I checked to make sure I have the larger YTX12-BS battery, as noted in the post above, and I do. Also, while the seat was off, I disconnected both terminals, and used a metal file to make sure both the cable terminal surfaces and the battery terminal surfaces were super clean, and re-connected & re-tightened everything, hoping maybe if was just some dirty connections. Well, no such luck. I still get the problem intermittently. Seems like the only real fix would be something in the circuitry to raise the threshold voltage, or a better / larger battery.
 
#19 ·
My 2012 Thruxton does this evey once in a while. I thought that it could be that the pistons were positioned on compression, and the loaded circuit would cut power, or there just wasn't enough juice in the starter unless it was off compression. It always starts on the next try. Some of my Harleys would do this. The practice was to always to tap the starter in case it was on compression in order to roll the pistons. The next press would start it. In any case, it shouldn't do this and Triumph needs to correct it. My Street 3 has never done this.
 
#23 ·
Hi Guys
I have a 2009 EFI thruxton and have had no end of trouble with this. I found that mine wont crank under 12 volts. I have hooked up a remote charge/jump plug and when I get the click click I can hook up my old batt and it starts. I'm sure my low voltage inhibitor is too high(12v) but dont know what to do. If you charge your battery I'll put money on it that it will crank. Nothing to do with cut out switches
Regards
Moth
 
#24 ·
I've had my SE since May 2011 (now done over 5,000 miles) and I have experienced the exact same fault from new. It’s not a frequent thing and there seems to be no commonality (other than generally when the engine is warm) to cause it to occur. I reported it to the dealer and they could find no fault. It’s annoying when it happens and wonder if it’s a common peculiarity with the newer Bonnies’? It would be great if someone could find a solution.
 
#25 ·
And mine has been doing it since new. (4 months now ~5500 miles) My battery hasn't died and I've never put it on a charger since it is ridden daily. I'd say it happens in about 1 of every 4 starts.

Somebody from a local AZ Triumph club suggested it might be the starter solenoid. I don't know anymore, I've basically given up, and am learning to just live with it.
 
#26 ·
Yep, I'm still having the same thing happen, too, maybe about one in every ten starts. Can't seem to find any particular pattern to it, except that it's mainly when the bike has sat overnight. Although it did do it once when I was leaving work (meaning it was only sitting about 9 hrs).
Anyway, one way to get around it is to press the start button right after you turn the key on (don't wait for the gauge needles to finish their sweep or fuel pump to pre-charge). Seems to always start right up doing that! I think it's because the battery doesn't drain down that little bit from the headlight being on, etc.. for those few seconds.
There's also another thread somewhere here where they sell a headlight cutout switch, which leaves the headlight off, until you flick the high / low beam switch once. That seems like kind of a hassle, though, I do like the headlight to be on automatically.
 
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