This is a oil pressure switch
This item will be item number 6 on the Lister Petter drawing
Please share what type of equipment your engine is being used in as this little bit of information could help someone else
751-40630 Lister Petter Washer
201-37291 Fuel control knob used on all models of the TS and TR engines
284359 Fuel filter housing with filter, Lister Petter, used on the AA1, AB1, AC1 and AD1 engines Micro Power System generators This is a oil pressureFilter housing and filter used on the AA1, AB1, AC1 and AD1 engines. Part number is 284359, filter part number is 201 13118 this filter is included with the housing though. The AC part number for this filter housing was AD600and the element was ACD60. The AC AB1 AD1 engines were used in a wide range of equipment, the AC1 version was used in the following equipment Amida series DLB Detour Lite, Compac P24 33 walk behind compactor, Ampac P33 24 walk