larmor precession

[bman!!]

i'm familiar with terminology used to denote rates of change in inertial and rotational frames, and the equation that links the two quantities, but working through a derivation/thought experiment to describe charge orbitting around another fixed charge in a weak magnetic field, it results in precession which is analagous to gyrscopic precession, but for the life of me, when working through the derivation, i cant explicitly see which term in the final equation describes this precession.

could someone point me in the right direction

cheers

p.s
the equation im looking at (it may be the wrong one) is:

ma(I) = k r + Qv(I) x B

where
m=mass
a(I) = acceleration vector in inertial frame
k = coulomb attaraction betwwen the charges, -QQ/4piepislon etc
r = radius
Q=charge
V(I) = velocity in inertial
B = mag field