exhaust pipe red?

[nihadpek]

Dear friends, I have the problem when my XF idling at the place about 5 minutes, the exhaust pipe close to cylinder start to be red. Regarding your expirience is it normal or not? Is it posible that exhaust valves do not close enough exhaust passage so the flame goes directly in the exhaust pipe and overheating it. Valve clearance done before 15000 km, and no change in performance of engine power, speed, axceleration... Thank you for any help.

[AoS]

What you see is the direct result of bad cooling because you lack the necessary airflow in the area where the most heat is produced. There's nothing wrong, just don't idle for that much time. It's bad for the engine and a waste of fuel.

In general, idling over prolonged periods of time isn't recommended for any engine; in the special case of our air-cooled engine this is even more so.

Regards,
Dirk