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Not starting after gassing up

3K views 26 replies 8 participants last post by  Joe Houle 
#1 ·
After two problem-free years with my '09 speedy, I now have a recurring problem. I have 15K miles on her now with original battery.
Unlike other posters, she starts up on first or second try with plenty of gusto, even when idle for a week and garage temp of 50F. The problem has occurred several times now: I stop to gas up, typically don't even get off bike, so takes a couple minutes I guess. I hit start and it starts to crank then stops. After a few attempts, my buddies heads begin to sink, then it fires up and I'm off. Yesterday, no such luck, but I was near a hill and roll started it. (after I learned that this should be done in second gear! I couldn't figure out why my rear wheel was locked in 1st gear). We later stopped a half hour for coffee and she roared to life without problem. I conclude that it is the very brief stop that is to blame...thoughts?
Thanks!
 
#2 ·
Lots of variables here; but my first question is: How do you maintain your battery?

Bikes in general (and perhaps S3's in particular) are very sensitive to the condition of the battery - and the condition of the connections in the charging and starting circuits. If the battery isn't very strong, this kind of thing can happen. The starter draws more current from the battery than does any other single component, which can drop the voltage available to run everything else when the starter is cranking the engine. The ECU requires a certain voltage to do its job, and it is possible that it isn't getting what it needs.

Or... it's always the battery. ;)
 
#3 ·
Hmm. I might end up with a new battery, but your reply doesn't explain what I'm experiencing. I have complete confidence that I can walk into garage right now and start her on first or second try. But after four problems after getting gas, I'm looking for downhills and considering leaving my bike running for quick stops. Perplexing, right?
My battery maintenance= riding every week. I put it on tender if I won't be riding. Terminals look great.
 
#4 ·
I don't have a solution for you but you might try searching for "hot start issue" or something similar. I've seen that type of problem on plenty of cars and a few different solutions. Seems like I remember a starter not liking heat on a friends car. He had to sit for 30 minutes after shutting it off or it would just click.
 
#6 ·
Does it seem like it cranks slow, or either doesn't crank and just clicks?

If the former, battery probably just past its best, assuming the generating system is good (check the voltage across the battery with engine running)

If the latter, look for broken key-switch harness - does situation change if you rotate the bars back & forward or pull on the switch cable harness?
 
#8 ·
does situation change if you rotate the bars back & forward or pull on the switch cable harness?
Damn, I think you may have nailed it DEcosse! Everytime I shut my bike down I turn the handlebars full left and remove key at the locked position. BUT, when I get gas I leave the handlebars neutral.

The "hot start" issue also makes some sense. I still have a hard time with the "bad battery" angle since it starts up easily after sitting for a week.

I'll do some testing...
Thanks for the ideas! (And thank you DEcosse for the group buy on the MOTOMFG stand!)
 
#10 ·
After sitting for a week (or even an hour) the ECU is nice and cool, and will have different needs vis-a-vis supply voltage than it does after it's gotten nice and hot on a ride. Not trying to defend my point, just providing some clarification.

:cool:
 
#14 ·
I've had the same problem with my 2010 Speed3. The symptoms were exactly as you're describing: my bike wouldn't start after short stops (typically gas station), but would start fine if left alone for 20-30 minutes. My local Triumph service has finally been able to diagnose the issue, and the problem was: faulty starter drew 180 AMPS when hot. They replaced the starter and starter clutch. All parts were covered by Triumph, I've paid for the labor.
 
#16 ·
Lad? Been a VERY long time since anyone called me that :p

Sorry FR, but that's just nonsense - the ECM draws well under 1 A - sensors draw at most only a few mA each and electronic components have negligible change in operational specs based in a fairly typical operating range from -40 to 150 C


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#21 ·
Sorry FR, but that's just nonsense - the ECM draws well under 1 A - sensors draw at most only a few mA each and electronic components have negligible change in operational specs based in a fairly typical operating range from -40 to 150 C
Definitely not nonsense, and it has nothing at all to do with how much current any of those components draw. The ECU sits in a rather small 'pocket' behind the engine, and will definitely be hot after the engine has been running a while. The electrical threshold change I'm referring to happens as a result of the change in temperature, not due to current draw. A typical CMOS circuit actually has switching thresholds that vary over a significant voltage range in that -40 to 150 C operating temperature range.

(I worked for 30 years in the semiconductor industry, dealing with just such embedded processors as the ones used in these ECUs)

:cool:
 
#18 ·
sergey said:
My local Triumph service has finally been able to diagnose the issue, and the problem was: faulty starter drew 180 AMPS when hot.....
Wow - now that would certainly do it

A fairly simple test to see if same problem would be to check voltage across battery when hot, with lights on - if not sagging significantly under 10A load from lights & is measuring over 12V still, measure voltage again while cranking - normal sag while cranking should be in the order of 11.0V with a well-charged battery.
Of course if battery is not fully charged it will sag further, even if starter is normal - the key would be how much it sags with just the lights
Compare your hot & cold voltages for these conditions:
Resting (off); lights/ign on & cranking



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#19 ·
Wow - now that would certainly do it
A fairly simple test to see if same would be to check voltage across battery when hot, with lights on - if not sagging significantly under 10A load from lights & is over 12V still, measure voltage again while cranking - normal sag while cranking should be in the order of 11.0V
Of course if battery is not fully charged it will sag further, even if starter is normal - the key would be how much it sags with just the lights
Compare your hot & cold voltages for these conditions:
Resting (off); lights/ign on & cranking



Sent from my iPhone using Motorcycle.com Free App

Like I mentioned, desulfate, top off, load test. I'm thinking its a simple tired battery.

10.3v is your magic "no start" number
 
#22 ·
Interesting background - me too, 35 years. ;)

So what temperature do you think the ECM is at, Ron? It is mounted on plastic and only direct heat source is internally generated or indirect off back-side of the motor which itself is at worst only 100C (& with a gas tank and shock in front of it incidentally) - haven't measured but would be surprised if ECM casing even is > 40C - and not much point in having a control system whose control is worse than the temperature of the engine to which it is trying to regulate! :D

We can agree to disagree on this
 
#23 ·
I'm actually more concerned about the power supply rejection factor. Most devices only guarantee performance over a +/- 10% range, and I could see the battery voltage dropping more than that under adverse conditions (during the start cycle, with a weak cell, etc.).

and yes, we can agree to that - especially since it's all speculation. If you've also been involved, then you know that 'in God we trust - all others bring data'. ;)
 
#24 ·
Finally had some time today to follow-up on comments and advice.
Popped the seat off and measured voltage across battery terminals and got 12.7V, turned on key (and lights) and measured 11.8, started up on 2nd try and got 14.5. (As an aside, I turned symtec grip heaters on high and still measured 14.5. I then turned my Gerbings vest up to high and measured 13.8V). I left it running in the garage (door open!) for 20 mins or so and still measured 14.5. Turned bike off and measured 12.9. Waited 4 mins and measured same. Turned on key and measured 12.2. Started up with gusto first try (of course).

Took it for a ride and stopped for gas. Started up on first try (of course). Rode home, turned her off and took measurements...same voltages.

BUT, when I tried to restart it failed! I popped the seat and got 12.8V. I cranked the bars all the way to the left and it started perfectly. Sounds like a faulty electrical connection up front, right?
 
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