Why wont my oil cooler work?

[davidatno5]

Hi, I've fitted an oil cooler to my R80 G/S 1982. To do this i've changed the inner pipe to one of 162mm, fitted the longer filter, have the correct shim and white ring washer and rectangular black washer fitted, changed the outer cover (BMW part) to accomadate the cooler pipes and clamped the cooler onto the cross bar just below the horn. The cooler stayed cold, I mean cold. Have taken it apart a number of time but everything seems OK. Change the oil relief spring at the base of the filter cannister (for bypassing the filter it it gets blocked) as the old one when examined was half the lenght it should have been and the cooler now get warm on long trips. Have a thermometer in the dip stick hole that reads 120C and the cooler maybe warm to touch say 25c. Any suggestions? Where is the oil going if not through the cooler?

Also how much should you retard the ignition when you have twin plugged?

Thanks David