Kyosho 96169 Air Cleaner Oil 100cc

Air filter oil for foam air cleaners, in a 100cc bottle.

A dry foam filter does almost nothing. The foam itself only stops large debris; it is the oil held in the foam that actually traps the fine dust particles that would otherwise pass straight through and into the engine. Running an unoiled or under-oiled filter is close to running no filter at all, and on a nitro engine that means grit scoring the piston and sleeve, which is damage you cannot repair and often cannot see until compression has gone.

Filter oil is formulated to be tacky enough to hold dust without being so thick that it blocks airflow, which is a real balance. Too much oil restricts breathing and leans out or richens the mixture unpredictably; too little and it stops filtering.

Re-oiling is part of routine maintenance rather than an occasional job. Most racers clean and re-oil after every run day, and keep multiple elements so a freshly oiled one goes on each time rather than waiting for one to dry.

The 100cc bottle is sized to fit a standard pit box. This is a universal nitro accessory rather than a model-specific part.