Forum bmwbike.com

When the bike has runned at slow speed the oil will hot and the bike smokes.
Rings and valves are new, compressión it's OK. I uses SAE 40 oil.
What coud I do to protect it.

I think the symptom of an overheated engine is seizing. The motor will begin to slow down. It will not smoke until after it has seized and the damage has been done. Upon cooling and restarting, it may then smoke.

I say this because probably your bike is not overheating at slow speed and the engine is not smoking from the oil being too hot.

Probably the engine is smoking because something is not right with the pistons and cylinders. At least, the rings do not seem to be seated (broken in).

You say the rings are new. Perhaps the piston to cylinder clearance was excessive, but not so great that a rebore to next oversize with new pistons was desired. So next oversize rings were used on the old pistons. But the oversize rings need to be gapped correctly, and the cylinders should be honed.

If these actions were not done, it could be the cause of the smoking.

Allan: Thanks a lot. I fell that the oil it is taking too much temperature that the normal rate.
Is it possible to put down the oil heat? How coud I do it?
Pablo

To say the oil is too hot, you need to be able to measure the temperature. There is a wide range of oil temperature, maybe up to 250F.
If you buy a deep aluminum oil pan, it will cool the oil a little. But I do not think that it will address the problem of why your engine is smoking.