Micro Basket Filters (Mystery Filters)These small filters are inserted into the inlet of the injector to catch fine particles before they reach the internal pintle.
Yamaha HPDI Mystery Filter
These filters fit Yamaha HPDI models (Z/LZ 150hp–200hp) and VZ models from 2000 and up.
Keihin Injector Micro Filters
Specifically designed for Keihin marine injectors used on Yamaha OX66 and various 150–250 HP models (1997–2005).
Universal Micro Filter Baskets 12mm x 6mm filters are often used for general marine injector servicing.
Replacement Process:
Replacing these filters requires specific care to avoid damaging the injector body.
Removal: Insert a small sheet metal screw into the filter basket until snug, then use a specialized extraction tool or vice grips to pull the basket out.
Installation: Place the new filter in the injector and gently tap it until flush using a brass-tip hammer.
Lubrication: Lubricate new O-rings with silicone grease or light oil during installation to prevent tearing.
