Hot bike = poor idle

I don't think I've seen this problem come across the forum before but I have been experiencing a problem with idling when my bike is warmed up.

Usually after a nice 20-30 minute ride, the bike is fully warmed up, I will stop at a light and I can hear the idle struggling to remain steady. I find myself having to hold the throttle open slightly just to keep the bike running! If I let off, the bike will stall.

After a stall, it starts up right away again but same problem. If it let it sit for ten minutes, then the bike starts up and idles fine until the bike heats up again.

I have no idea where to even start looking to address this problem. I can't figure the carbs (mind you I'm no carb expert) since the bike runs fine initially.

Any thoughts? At this point, I'm afraid to go anywhere on the bike for fear I can't get home!

 

i would venture to guess a sync and/or mix issue, my bike acts rather similarly. Runs very strongly, but after a bit riding the idle is unsteady just like yours.

 

What color are the spark plugs?... I wonder if your pilots are set a tad rich.

 

Probably too rich on the idle mixture.

 

I recently synched and colourtuned. Plugs are all tan. I did some tests last night at different rpms (2k, 4k, 7k) for 20 seconds each on the center stand to see how the plugs look. Always tan.

Maybe I need to colourtune again with the bike fully warmed up? I'm not sure I did that last time.

 

you could bump your idle up. IMO you should only adjust the idle speed when the bike is warm. Run it for 20-30 min then with your gloves on reach in and turn the knurled idle screw up to where you want it. You may have a little higher idle when cold but if all else is in order as you say with the plugs being a light tan you will be fine. Every time I have ever synced carbs I had to readjust the idle speed as well.

 

I'm having a very similar issue with my 550 Maxim. After all I have done, checked, and adjusted lately I am beginning to think my butterfly shaft seals are going bad. I haven't been able to get a reaction spraying them with starter fluid, but I am getting the erratic idle which I have read may be a symptom of bad seals and I can see where fuel has previously lacquered around and under the C-clips. Sometimes you can see they are slightly wet, but never dripping.

 

What happens AFTER the light turns Green?

How does the Bike get "Out-of-the-hole"?

Does it accelerate without stumbling or hesitation?
Does it cough a bit and then go?
What exactly does it do?

We need to know how the Bike accelerates "Off-Idle" to determine how much of an adjustment or other tuning there is to do.

 

remember to set the idle when the bike is warmed up