Tiger 1050SE intermittent starting issue

[IanEll]

I have a starting issue which is subtly different to all the ones I have read about. The bike is a 2009 Tiger 1050 SE. It runs perfectly, but if it's left for a while it won't start.

What happens is the clocks do their sweep, the starter cranks twice when you press the button, then it stops turning over. If I cycle the ignition it will do this repeatedly.

I fitted a new Enduroline  AGM battery and the behaviour continued.

If I fit a jumper battery the bike will start and run normally. Once you have started it once it will start again; until now it's worked fine all day, starting normally until you leave it for a few days again.

Today I rode 12 miles into town , left it 1.5 hours, and needed to jump it again. After that, 2 shorter stops of 15 - 30 minutes did not need a jump.

When I got home I checked the voltages - 12.6V with ignition off, 12.2V ignition on and pump priming, 10.5V cranking, 13.6V at idle. Cranking voltage is marginal so I suspect it's probably just a bad connection somewhere, but I wanted to check if there were any known generic issues that might cause these symptoms?

I'm familiar with the normal diagnostic cycle and I'm going to check voltages after a couple of days rest, across the starter, look for parasitic drains, bad earths etc but if anyone can short-cut the process I'd appreciate it. Cheers! 

[ZuluTiger]

https://www.tiger1050.com/index.php/topic,43093.0.html

[Paul2bikes]

Isn't that a budget battery? You need a Yuasa YTZ14S

[Sidewinder]

Do you have any electrical mods or accessories?  13.6v at idle is on the low side, given the spec is 14/15v which makes me think stator/RR probs. - what V at batt do you get around 4000revs?
What exact battery is it, did you charge it before using?

Also, what Paul said.

[ZuluTiger]

I just did a quick check on my bike fitted with a recently new YTZ14S, using a high-quality Fluke 87. It has been on a Tender for a few days. My no-load steady-state voltage (ignition off) was 13.0 after removing the charger and letting it settle for a minute. This actually surprised me as I expected closer to 12.8. Running at idle, with headlight load off and on, the voltage was 14.4, regardless of the load. I have a Sport setup so dual-low and high beams. It made no difference - 14.4 VDC. I expect this would have dropped if I'd let it sit for a while but for the few minutes I let it idle, it was steady.

[IanEll]

Thanks for all the input. I'm pretty sure I've found the problem. The PO had fitted an accessory socket with USB adapter wired into the battery (with its own fuse). Having removed this the voltage drop has stabilised. In 3 days it's gone from 12.86V to 12.80V, whereas before it would have been down to 12V or lower, and it fired up very happily this morning whereas before it wouldn't have had the guts. Another accessory for the bin! .

[Sidewinder]

Yeah usb adaptors can draw power even when nothing is plugged in, shitty china made ones more so.

Would still keep an eye on your charging voltage though.

[ZuluTiger]

Sounds like you have a good first step. Bear the battery comments in mind for the future though.