I'm a new member and have been lurking on this site for years. What a fantastic, helpful resource! I have now signed on hoping to enlist the knowledge of the collective with a specific issue I have with my bike. It is an otherwise trouble free 2007 DL650 non-ABS, California model. I have approx 70,000 miles on it and have owned it since new.
I am experiencing an idle-down to cutoff-and-quit condition after rolling off the throttle and decelerating, esp. coming off a freeway offramp to a stop. It seems to be connected with dampish/cool/foggy weather. A typical scenario is: I'll be humming along at 5k rpm on the fwy for 1/2 hr or so, exit at an offramp, using extended engine braking in 6th gear (throttle completely closed) before pulling in the clutch and applying brakes to stop. As soon as I pull the clutch, the engine idles down to 1000 or 800 rpm, hesitates there for a brief instant, then dies. This problem is very intermittent (the bike usually runs fine) and I cannot repeat it for my mechanics on demand, nor can they replicate it. It usually happens late at night or early in the morning under cold/foggy conditions, but has happened in dry warm conditions as well.
The throttle bodies were synchronized less than 5k ago (they apparently weren't much out), and the idle was set correctly. The engine always idles at the correct 1300-1200 rpm, except when its acting up. The bike is otherwise maintained according to the Suzuki maintenance schedule, although I have skipped the last valve check (the valves have never gone out of spec).
I have had the bike die on me twice, in the middle of intersections when I go to accelerate, so it is a serious safety issue. The problem is so intermittent however I cannot get a solid diagnostic read. The Suzuki dealer (CalCoast Motorsports) has tried to diagnose the issue without success, they could not replicate the problem in test riding the bike for a couple days.
I suspect a bad TPS, given the information from this forum. My questions are two: can anyone validate/invalidate the TPS theory, and what is the part number I need to order to have it replaced?