Weird sparking problem

[Tip451]

I have a 2009 XB12XT that I love, it is stripped down to be a sport bike with no bags, triple tail, or hand grabs on the back. First bike I've loved with a real passion since my Bultaco Metrallas.

Anyway, I just changed the plugs to the NGK DCPR9EIX Iridiums. After a few minutes of riding it acted like it was fouling the plugs and started cutting out. I thought maybe the plug wires weren't on right -- that could have been true, as I was having real problems getting the wires back on. Anyway, when riding, it rapidly crapped out worse and worse and pretty much stopped running as I put it in the garage. Pulled the new plugs, they were badly fouled.

On this bike when you turn on the key and turn the kill switch to the run position, it seems to be normal that the plugs spark continuously for a couple of seconds. That works fine.

But when the starter motor is engaged and it turns over, it will not spark at all. It does that 1-2 second spark really fiercely so the coils must be fine. Thought maybe not enough battery power to crank the starter and generate a spark, so I used a second battery with jumper cables. No change.

Anybody know what could cause this? Thanks for any help.

 

[anrkizm95]

did you get the iat sensor plugged back in?

 

[user_deleted]

^^^[up] what brian said as usual. if the bike was running fine prior to your plug change go back and double check your work. either something is disconnected, the wiring to coil and coil to plugs is compromised, or even the velocity stack to the throttle body might not be properly seated if in fact you removed the plastic airbox base during plug install. check your work again. i've never seen DCPR9EIX plugs foul.

 

[Tip451]

Thanks so much for getting back to me on this! I think I'm going to like being part of this forum. By the way, I am now working at Chaparral Motorsports making some of their web videos if anyone is familiar with that store.

Anyway, I just bought the bike a few weeks ago, don't know it that well yet, so I must ask "What and where is the iat sensor?" I'll be searching that, but don't know if it will come up, so that info would help.

As for the plugs, right now I'm not dealing with the fouling problem, have the plugs out of their sockets and plugged into the plug wires with cables to ground them. But I do think the iridium plugs fouled in the first place because the plug wires were not on all the way and the spark was jumping a gap to get to them, so it ran -- for awhile.

I consistently get a beautiful spark during that initial period when the fuel pump is priming or whatever is happening during those first few seconds before you can actually activate the starter motor. It just won't give any spark once being cranked.

 

[Tip451]

Okay, intake air temperature sensor. I did have the upper air cleaner cover off to inspect the filter, so if I remove that again I should see the iat sensor and can check to see if it is plugged in. But even if unplugged, would that completely kill the spark when cranking with good, un-fouled plugs in the wires and grounded but out of the cylinder heads?

These bikes got me back into motorcycling. I was a road racer in the mid 70's, mostly on Kawasaki triples and in the late 60's on Bultaco Metrallas. Haven't ridden literally for decades. Met Erik Buell back in-the-day when he was riding for a guy with a TZ750, in fact he slept on my couch at least one night.

Fell in love with a Buell parked up from my old job in Burbank, CA and started craving. Ended up working at Chaparral Motorsports and somebody traded in a nice 2009 XT for a KTM dual sport. I really wanted an XB12Ss or STT but I could actually get the XT because they gave me an inside deal on the trade-in and ALSO got me decent financing. Basically I stripped it down and like it a lot with the compliant suspension it has. Put on the low seat, Michelin Pilot Power 3 tires and some Renthal Streetfighter bars and it is basically this poor boy's faux Ss.

 

[user_deleted]

What and where is the iat sensor

affixed to rear of your airbox base plate which is the very large black moulded plastic plate that attaches to frame with four large torx screws. the plug attaches to the IAT sensore from underneath the plastic base plate.

 

[Tip451]

Problem solved, thanks for your help. I did mention that I was looking for spark on plugs that were not screwed in but were just plugged into the wires and grounded with jumper cables. As it turns out, the plugs will not fire when out of the engine. Don't know why, I guess just a smart ECM. I merely installed the plugs and the bike started immediately, evaluating the spark with the plugs out does not work.

So if anybody in the future has this issue, that is the answer, just screw in the plugs, pop on the plug wires, and the spark should be restored. Sorry for the newbie ignorant problem, and thanks again for your help.

 

[Beastrider]

that makes no sense to me. should fire if connected to earth.