I'm glad I found this thread because my FJR has been driving me nuts. Its a 2005 I bought used a year and a half ago. Unfortunately a lot of my riding is in city traffic where I experience the 1500-2000rpm sluggishness/burbling a lot. I hear exhaust popping at idle and up to 5000rpm. Its really bad just under 2000rpm, which is also where the surging/hesitation/rpm hunting is the worst, but I can hear slight popping at all rpm's if the engine isn't under load and the throttle input is constant. Is the popping I hear normal lean stuff and coincident with the surging others have commented on? One dealer said "these big I-4s don't like low rpms" and the other said "they all do that". I did the Barbarian/CO mod to no effect, cleaned wiring harness that can cause problems, TBS, etc., but to no avail. Am I just experiencing the normal GenI FJR behavior, and if so does a PCIII take care of most of it? I would gladly pay $300 for a PCIII (or a lot more, dammit!) if it fixed a bike that's otherwise the exact bike I was meant to be with! Basically I just want to know if what I'm experiencing is common and can be fixed.
dlfunk,
It depends on what you mean by your use of the word "popping".
Do these engines all idle a bit
roughly, either warm or cold? Yes they do. They all have what sounds like an intermittent "miss" when they are idling. I have never heard an FJR that idles completely 100% smoothly. Here's a link to
of the uneven idle sound of a healthy FJR. this one is a second gen, but they all sound pretty much like this.
[edited to add] If someone thinks they have a bike that idles significantly smoother than the one in the above video, please post up a video. I'd sure love to see it.
Do all stock
1st gens have the lean surging condition at low load / low throttle openings? IMO, yes they do. It feels like the bike is slightly speeding up and slowing down, in a randomly occurring pattern when the bike is held at a steady throttle opening. It feels similar to the way the bike feels when you are riding through gusty / turbulent air, but happening even when the air is completely still.
Over the years, and on different bikes, I have found that not everyone is sensitive to this condition, which is why some people think they don't have it when they do. It is just a
sensation, and not really bad enough to cause any driveability issues. Some folks just live with it. This condition can be fully ameliorated with a PCIII. BTDT.
Do all stock FJRs have an abrupt throttle transition from trailing throttle (throttle fully closed, engine braking) to when the throttle is first cracked open? IMO, yes they do. It's because the ECU cuts all fuel to the engine under trailing throttle, so when you first crack the throttle open the power comes on abruptly. The PCIII can also help soften this transition with appropriate fuel mapping in the low and zero throttle areas.
Do all FJRs have actual backfires (popping sounds) from their stock exhausts at idle and during cruise? Not in my experience. If you have this happening you should investigate further.
Hope that helps