suddenly stalled out, won't restart

SD newbie here -- bike quit on third brief ride after purchase; I just bought it from original owner last week, and he claimed to have never had any problem with it. He seemed to have been meticulous in caring for it (i.e. his other bikes & cars all looked pristine, he had all receipts/records - including one for a new battery last year, bike didn't have a single blemish anywhere). I've ridden it less than 25 miles. No hint of a problem until this failure.

Bike details:

07 with only 1400 miles; FMF Apex slip-ons, PCIII w/custom map, MH airbox & SAS block plates; many other accessories, but all cosmetic (all mods done by previous owner)

Event details:

While cruising at low speed (45mph) engine cut out suddenly; no sputtering or other drama, just as if I'd hit the kill switch. Now it will crank, but not fire up. Nothing unusual on the display, and the fuel pump makes its normal sound when I turn the key. Visual inspection of all exposed wires & hoses yields no apparent cause. Oil and coolant look clean.

Diagnostic efforts so far:

Checked fuses and #5 was blown; this goes to the fuel pump relay, if it's the same as '05 Adventure (for which I have a repair manual). Replaced fuse, but no change in problem.
Checked angle sensor in headlamp mask; it was secure.
No obvious problems with sidestand or clutch switches.

Where should I look next?

Many thanks for your thoughts.

PCIII wiring traced to BGC and ground terminal on battery -- all looks good.

BTW, found fuse listings for SD, and #5 is fan, not fuel pump relay, as on Adventure.

I would do a search for side stand switch issues here. A friend of mine knew someone that had that switch fail during a ride and they ended up pulling it apart on the side of the road and bypassing it in order to get it started. Apparently it's a common enough occurrence that a bypass kit is sold for it. I've been meaning to disable mine for a few months now just to be proactive. Good luck!

Here's a good post about it from a different forum.

http://www.advrider.com/forums/showthread.php?t=694524

Seems to me that a sidestand (or clutch) switch problem would prevent running only with the bike in gear, and my bike won't run in neutral (with clutch in or out, and sidestand up or down). Can these switches prevent running in neutral too?

Check the fuel line disconnect, push them together and make sure they're seated. Had the same thing happen to me on a BMW, went through everything just as you guys are suggesting, sent it back to dealer. He checked fuel pressure, put the line back together and it ran fine. (the factory had zip-tied the line to the frame so tight right at the connectors it had somehow vibrated and pulled just out of being seated)
I just went out to the garage and checked, they're the same connector on both bikes!

Thanks for all the input. After carefully checking everything suggested and making no progress, I took it to the dealer today. They called me just now to say I need a new fuel pump at a cost of nearly $800 for parts and labour. They blamed ethanol for destroying the pump's guts, adding that this was probably made worse by the fact that this bike has been sitting for much of its life (only 1400 miles and it's an '07).

I can try to find pure gasoline or use an ethanol-antidote additive from this point forward, but now I'm wondering what else might need attention on this bike -- either because of ethanol, in particular, or because the bike has been dormant for most of the last four to five years. Any ideas?

I was very lucky that this time the bike broke down on a quiet street near my home, and I could easily and quickly retrieve it with my trailer. But now I worry that something else will fail when I'm far from home and/or on a busy highway. I'd much rather try to address likely sources of trouble before they leave me stranded. It sucks to have my confidence shot down on a bike I've only owned for a week and ridden less than 25 miles. Reassurances would be welcome from those with reliable SD's.

Thanks, Agro. I was thrown off by the fuel pump's sound, too. The mechanic told me that the servo was indeed still working, but that the pump (impeller?) was not turning. I don't understand how this could be, but I didn't have time to ask for more explanation.

I checked the fische and there's no way to buy individual parts to rebuild the fuel pump. However, after sleeping on it, I've decided to get the pump via an internet source that will save me well over $100 on parts costs (cheapcycleparts.com). I'll still be out the dealer's diagnostic charges, but I'll know everything has been put in properly when I'm done. I share your mistrust of dealers and their service staff. As far as I can tell, removal and replacement of the fuel pump is pretty simple and straightforward. I've got to remove my tank to install MotoHooligan's rear brackets anyway...

Change all fluids, brakes, forks, engine. One of my riding buddys well kept R1Yamaha air box was filled with bird food a mouse stored away thru the winter, Ran like crap in the spring. My guess on your bike was a pinched gas tank vent. I start with the cheapest items first. That quick check for the pinched gas vent is to open the gas cap. I have had good luck buying from this site and e-bay. I bought a good tank with pump but no cap, a like new raditor and a seat for $500 from this forum. There is a SD in Texas that is getting parted out on e-bay. I saw a few gas tanks. I bet you can find a fuel pump. Take it ez with the old tyres.

Agro! -- New OEM fuel pump from dealer and most online sources cost between $440 and $480 (local dealer wanted $463); cheapcycleparts.com sold it to me for $316. None of these prices includes the o-rings ($62 most places, $33 at cheapcycleparts.com) or the fuel filter set ($130 most places, $86 at cheapcycleparts.com). I would have bought all three items together, but cheapcycleparts.com was out of the filter set, so I'm going to go without new filters for now -- since the bike only has 1400 miles on it, I'm hoping I'll find the ones in there to still be fairly clean.

DougFir -- I, too, wondered about a problem with tank venting and opened the cap when it ceased running. Of course, this time, that didn't help. MH airbox luckily doesn't allow varmint entry. Thanks for the tips on sourcing parts; I'll definitely search here next time. Already planning to change all fluids everywhere. Wondering about fork oil change -- this is obviously a question for elsewhere on the forum -- but in case someone following this thread has done that swap, how much fork disassembly is required? I've worked on many KTM dirtbike forks, and non-WP streetbike forks, but this is my first KTM streetbike.