  We measure the 2-1 cumulant correlator power spectrum $C^{21}_l$, a
degenerate bispectrum, from the second data release of the Wilkinson Microwave
Anisotropy Probe (WMAP). Our high resolution measurements with SpICE span a
large configuration space ($\simeq 168\times999$) corresponding to the possible
cross-correlations of the maps recorded by the different differencing
assemblies. We present a novel method to recover the eigenmodes of the
correspondingly large Monte Carlo covariance matrix. We examine its eigenvalue
spectrum and use random matrix theory to show that the off diagonal terms are
dominated by noise. We minimize the $\chi^2$ to obtain constraints for the
non-linear coupling parameter $f_{NL} = 22 \pm 52 (1\sigma)$.
