The bonnet catch on my 500R was not reliable, probably because the pressed steel hook had been bent and straightened several times. I searched for any information on how to fix it but found nothing useful so here is what I did.
Firstly I bought a new aluminium catch. Unfortunately I was not happy with the quality and in particular the drilled hole which was oversize, tapered, and drilled eccentric to the cast boss, so I made my own.
The original catch pivots on a pin that is welded to a bracket that is welded to the front panel. I was apprehensible about removing the pin but as it happened it came off easily after gripping with mole grips and twisting back and forth. The retaining weld was very small but left a hard nib that was cleared with a small burr in the electric drill.
A M8 bolt was used as the new pivot. Long bolts have a section of plain shank near the head so one was chosen of just the right length to have this plain shank act as the pivot pin and the thread cut down to suit. After fitting the new catch with a spacer washer to minimise axial movement the bolt was fitted with a nyloc nut to hold it in place.
The spring and cable were reattached, (I was appalled by the crude cable fixing, but it works) and the new catch tested and as a precaution the catch was first lassoed so that it could be pulled open if need be.
