05 FSE 450 Hanging Idle
 

Gentlemen of almost infinite wisdom, I present this problem ...

Last year I was brought this particular bike because of a no start condition. It turned out that three of the four valves were totally coked and would not seal. That issue was resolved and the bike went back to its' home.

It recently found its way back to me, first for oil leaking from the cam cover (not enough goop on the half-moons - it had been sealed when it left but apparently loosened up over the winter) and an apparent coolant leak.

The coolant "leak" is actually discharge from the overflow, which is not surprising given that the head pipe will glow red if the bike is stationary and idling for over 45 seconds. The cap is a Bandit or Pit Posse rated at 1.6 bar. The fan runs and dumps a lot of heat. On the road I could get two or three miles before the pop-off popped off and coolant dribbled out. I'm going to see if the new 1.8 bar cap from the '11 2Ts will help with this.

More troubling is a hanging idle. The bike starts well, runs at a fast idle, and then slows down somewhat (but still not slow) when it warms up. The engine speed dips when you start to ride away, but tends to hang up when you release the throttle. I can pull the idle down with clutch out brake applies, but I would rather it drop on its own. Like so many others stated, I believe the bikes owner has had every sensor checked for function and they came back positive.

Thoughts?

I have same bike and I seem to remember a similar issue.

Check the throttle cable for broken or freyed wire at both ends. Even clean and lube throttle cable.

If the idle has been set, not messed with and sensors are right then check your throttle cable.

I recently sold my 05 450, and only the other day the new owner asked me bout the same idle problem. The lean condition you describe, could it be a dirty injector not letting enough fuel through, or even the fuel pump not delivering fuel pressure up to spec?

might wanna find someone with the diagnostic software and plug in your ECU.

It might be set on the lean mapping. That would explain the pipe glowing so quickly and it getting hot, but i dont recall elevated idle in the lean mode.

elevated idle could be an air leak in the intake, between throttle valve and the engine.
check with brake cleaner, spray everywhere on the intake tot the engine, becarefull not to spray on your glowing exhaust!! :eek:

Fired up the scoot and shot brake clean at the intake - nothing :D

The owner said that he had the TPS checked by shipping the complete throttle body to GoFasters and that it was spot on, but I would think the engine (and ECU) it was attached to would make a difference :confused:

Best thoughts for cleaning the injector? If that fails, I remember GasGas making a big deal about being able to go to the local Buell :eek: dealer to pick up a replacement.

I believe the blue/yellow wire is disconnected, but I'll double check.

I had problems...and part of the problem was the ECU...the so a member on here checked it out for me and for whatever reason the fuel trim was set waaayyyyyyy off. Don't know why. He reset it and it ran fine. in the mean time I also bought a new ecu. So if you need one...I have two!

There should be an air screw in the throttle body. It may be worth a check to see if it is still there? Could have fallen out or been tampered with. This would severely lean out the mixture at idle and have less effect at higher rpms. Failing that it's probably time to check the sensors with the software and probably the fuel load adjustment.

injectors dont just run leak thats not the issue, if an injectors stuffed it will barely run i would look at (trim ECU) or the intake boot, they split right under or inline with the clamps, i would remove to check it out rather than rely on a spray test, if its leaking it would be sucking air in, my 08 split one and it idled at 3000rpm ... failing that its sounds like a lean issue red pipe is the giveaway.