When I start my bikeWR426fthe exhaust pipe and the boiler immediately gets very hot. And the part of the exhaust pipe that's close to the engine gets red but the engine work fine. Is this normal?

Due to the type of metal used in the production of the exhaust pipes, it is very normal for any motorcycle exhaust pipe to turn red when running, especially at an idle.

When the bike is moving the air cools the pipe. That is why the street bikes have chrome covers, so you don't see the red/blue pipe.