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View Full Version : Flat spot under accel



dyllon33
02-07-2015, 04:14 PM
As the title states, on my xb9r I sometimes experience a "flat spot" under acceleration. It's not every time, but its often enough to notice. While at a constant cruising speed (say about 3000 rpm? Haven't ridden in a few months) if I roll on the throttle it will sometimes get stuck in this flat spot for a second, then accelerate as usual. I read issues about TPS a lot so I'm wondering if that's not my issue. The only performance mods I can think of are my D&D exhaust and K&N filter.

So I've been thinking about trying ECMSpy because maybe it just needs the TPS reset. But will I need further tuning if I do the airbox mod and add a right side air scoop in addition with my current mods? Any other performance mods I should do while I'm at it?

Sorry for so many questions lol. Thanks in advance for any input. :beer:

user_deleted
02-07-2015, 05:20 PM
year of your XB9 would help. if it is 2003-2007 ecmspy works well...if 2008-2010 then free tunerproRT seems to be the gateway of choice into your ecm by most all board members. a right side(RSS) air scoop assists in cooling the rear cylinder and highly recommended in warmer climates and temps. has no affect whatsoever on tuning. XB's typically fuel pretty nicely from the factory but there's additional performance and smoothness to be found by "tuning" your stock ecm. flat spot? i would start with a tps reset as you mentioned, check for any trouble codes stored in your ecm, fresh premium fuel, fresh plugs (NGK DCPR9EIX), a bit of sea-foam to treat and clean the injectors, and a 25 mile gentle ride in "learn mode" after the tps reset. these are basics that many times resolve modest fueling issues and give you a base-line from which to work. also check your plug wires carefully. they're short and in a bit of a hostile environment and can fail. you do NOT have to rotate your motor to do any of this.

go cytocis
02-07-2015, 05:35 PM
I'm in agreement with lunatic above.

The XBs in general are well-known for their rough mapping & hesitation at lower revs.

An EBR pre-programmed ECM with aftermarket pipe of your choice & K&N filter is another way to see big improvements in throttle smoothness & response.

dyllon33
02-07-2015, 05:48 PM
Sounds like a good place to start. Thanks for the input. It's a 2003 btw. Is there anything else I can do to squeeze more power out of it without getting into the internals? Not looking to make it a rocket ship, just anything relatively small and cost effective. I've always worked on cars, but just got this bike a year ago so I figured I'd ask the veterans [up]

user_deleted
02-07-2015, 09:40 PM
Is there anything else I can do to squeeze more power out of it without getting into the internals? Not looking to make it a rocket ship, just anything relatively small and cost effective.

get more air into the motor.....you've already gone that route
get more air out of the motor.......you've already gone that route.
your ecm manages among other things the coil firing the spark plugs(timing) and when the fuel injectors open and for how long. this is over simplication on my part but what john mentioned above really perks up a stock XB.