Will dnf remove kernel underneath it self?

edit

Yes, dnf will remove the running kernel, do read the transaction summaries before continuing. To keep that kernel, and still get updates:

Get a list of available kernels with full name-version-release:

rpm -q *kernel*
kernel-4.2.0-0.rc2.git1.1.fc24.x86_64
kernel-4.2.0-0.rc2.git2.1.fc23.x86_64
kernel-4.2.0-0.rc3.git0.1.fc23.x86_64

Explicitly remove the newer kernels (presumably you know the newer ones aren't good on your system):

dnf remove kernel-4.2.0-0.rc2.git1.1.fc24.x86_64 kernel-4.2.0-0.rc2.git2.1.fc23.x86_64

then you'll have one kernel instead of three, and you can get the newer kernels for testing.

Alternatively, you can use the --exclude option to dnf to exclude a package one time from a transaction.

man dnf.conf says you use exclude= to prevent modification by dnf. Using @randomuser answer, slightly modified, rpm -q kernel; add the full name of kernel to the list. (Checked the rpmquery string: it did nothing.)