After putting the bike back together I expected to need some time to get the TPS set just right again. I've adjusted it a few times, it still doesn't feel "just right". At low speed, in 1st there is a bit of a surge/abrupt drop in RPM once the throttle gets opened or closed past a specific point. As usual, I warm the bike up, check that the idle is set at 1300rpm, turn the engine off, have it in dealer mode and adjust the TPS to show in the middle. These are the instructions from the service manual, they're not complicated. I've tried to adjust it so that it just moves over to the middle from the bottom and also tried it so it just moves over to the middle from the top.
I've just been playing with it to see if I can get it any better. If you move the TPS while the bike is running the revs change. If you move it so it's all the way with the marker at the top, it's sputters, goes to idle very low and will soon die. It sounds terrible, as if it's idling on one cylinder almost. If you rev it a bit it sounds bad, like the timing it far out. If you move it all the way to the other side so the marker is at bottom then the bike seems fine, it idles well, revs decently and doesn't appear to have any real issues. This is the reason I try to get it adjusted so that it's just just moving over to the middle from the low position. If, while the bike is running, you move it away from the lowest extreme position, there is a slight pick up in idle RPM until a specific point after which is idles like a dog all over again, even before the indicator moves.
When you start the bike the position of the line on the display changes from what you've adjusted it to the lower position, the bike idles at 1300rpm as set. The bike seems to idle fairly well, perhaps a tiny bit of hunting, talking 100rpm each way at the most. If I then open the throttle slowly, pausing every couple hundres RPM the line moves from the bottom position to the middle position at around 2300 to 2400 rpm, also with a tiny bit of hunting. I didn't try to make it go from middle to top as I don't think that's as important and the neighbours might already be getting annoyed with me today.
After all that, here are the questions:
- does anyone know if it's right for the indicator to go from the middle position to the lower position once the bike is started?
- assuming it is, does anyone know where it should be changing to the middle position if you open the throttle slowly while the bike is running?
