KTM 990 SM-T | DOIN’ TIME

Long-Term Update: Settled in and enjoying the ride.

RKExcel chain
On the maintenance front, an RK Excel 525GXW O-ring chain with black side plates was installed.@Motorcyclist

WRIST: Marc Cook
MSRP (2013): $13,999
MILES: 14,910
MPG: 37
MODS: RK Excel chain
UPDATE: 11

I feel like the mods and tweaks are coming slower on the KTM as I settle in and simply enjoy riding it. In my spare time (ha!), I will occasionally tweak the fuel map using the TuneECU software, but I feel like I'm reaching the point of diminishing returns. I did run a map that forced the secondary throttle bodies to full open all the time, but the bike began surging in the midrange. No doubt an afternoon on the dyno would give me the fuel or ignition tweaks I need to sort that out. But, as I said, I'm kinda into riding now.

On the maintenance front, I installed an RK Excel 525GXW O-ring chain with black side plates (rkexcelamerica.com; $246) in part because I wanted to illustrate chain-replacement procedures in last month's issue. But something interesting happened: The KTM got quieter. While the stock chain, with about 14,000 miles on it, passed the quickie "sprocket pull" test—if you can draw the chain off the back of the sprocket and see more than half a tooth, it's done—it was starting to exhibit some side-to-side play.

Probably the stocker could have run longer, but the RK Excel is a nice upgrade, with black side plates and included rivet link. The quiet part? KTMs of this design are notorious for “chain slap,” where the chain runs over nylon guides above and below the swingarm pivot. At certain engine speeds and loads, the clacking can be pretty obnoxious. Without question, the new RK is a lot quieter (at the same tension) than the original chain. Not exactly breaking news but a happy observation.

Remember when I said I had the oil change down to a quick job? Maybe I should be a little less quick. About 400 miles past the change, in a parking lot at Mazda Raceway Laguna Seca, I noticed the case just under the filter cavity was wet with oil. It wasn’t exactly a leak, but it wasn’t dry either. I cleaned it thoroughly and kept a close eye on it for the return part of my trip. By the time I got home, it was definitely leaking. Careful inspection after removing the oil-filter cover revealed that I somehow had nicked the O-ring seal. A new O-ring fixed the leak. Lesson learned.