1 cylinder? Fluke or developing problem?

[TobyDanger]

Had a weird thing happen last night with my S2R800.  Not sure if it was a fluke or something I should be worried about?

After work I rode to meet my gf for dinner.  The restaurant was only about a mile from my office and the bike was fine getting there.  Gas light came on, but it was time.  Had dinner and walked around a bit.  Came back to my bike (parked outside, maybe 48°F, fine layer of condensation forming on it) and it fired right up, but sounded a bit off (bupbupbupbup). 

At first I thought the idle was just really low, I had the fast idle at 50% already so I pulled it back to 100% but it was still idling funny just below 2k rpm, where it should be up around 3k or more with full fast idle.  I let it warm up for 30-45 seconds and started to ride off, hoping to warm it up.  I rode about 30 feet but I had almost no power, and it bogged down badly, like I was trying to ride off in 3rd gear. 

I stopped, turned off the bike and turned it back on, fired it up again, but it sounded the same.  I tried blipping the throttle to get the rpms up, and it responded ok, but when I tried to pull off, again it bogged down with no power.  I tried feeling both exhaust for pressure before stupidly realizing there is a crossover.  I shut the bike off once again, fired it up, no change.  Tried blipping the throttle some more and after a few higher revs, it picked up and sounded normal once again and rode home fine.  Rode it out to get gas this morning and it was fine then too.

My thought is that maybe one cylinder wasn't firing at first?  Maybe a bit of low gas crud sucked into an injector?  Or maybe sitting outside (garaged at home and work) it got colder than normal and I just needed to let it warm up more?  Anyway, is this something I need to worry about now, or just if it happens more often?

Thanks!

[ducpainter]

Sounds like it's running on one.

Check to see if both header pipes are getting warm. Be careful...they're hot if it's running.

You might have sucked some water out of the tank and fouled a plug. The filter should protect any crud from getting to an injector.

[DucatiBastard]

I had a similar (possibly the same) issue with my bike, an '06 S2R800.  My problem didn't vanish like yours however.  It started after I installed pod filters, the bike would only run on one cylinder, the horizontal.  I tried a bunch of things, new plugs, swapping injectors, wiring tests, finally took it to the shop to fix.  They found a broken ground wire deep in the wiring loom.  It had corrosion at the break, was probably weak and broke when I moved the loom to put the filters on. 

Check the easy and cheap stuff first.  Make sure each cylinder is getting fuel, spark and air.

My guess is the cylinder isn't always getting spark.  At this point it seems like the potential weak spot is iffy.  The problem may return.   

[TobyDanger]

Thanks for the confirmation and the tips.  Fortunately it has only happened the once so far, but I'll know what to check if it happens again.

[TobyDanger]

Check to see if both header pipes are getting warm. Be careful...they're hot if it's running.

Well it returned this morning after a week of running normally.  I recognized it right away this time, tried a simple restart, and a few revs, no change.  Got off and learned several very important things very quickly.  Wearing my winter riding gloves, I did a quick tap on the front cylinder exhaust, double tap, triple tap, touch, felt slightly warm through my gloves.  Walked around to reach in and tap the rear cylinder exhaust and INSTANTLY my glove fingertips melted on the header and gave me a very light burn through the heavily insulated gloves.  The bike had only been on for what felt like 30 seconds or less (maybe a minute) and boy was it hot already!  I had no idea it would get that hot that quick...

So I guess I know it's my front/horizontal cylinder that wasn't firing this morning.  I tried starting it up again and after a few revs it kicked in again.  I'll check the plug when I get home tonight...  I feel like it shouldn't be the gas, as I was running very empty when it happened the first time and I've put a tank through since then.  Then again, it's from a fairly low volume ethanol free Spirit station just down the street so maybe it's the same batch of gas.

[motoxmann]

just to be totally sure, put a new set of spark plugs in and make sure they are gapped correctly.
also wouldnt hurt to remove the spark plug wire caps, trim the ends of the spark plug wires, and reinstall the caps.