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What this video covers

A marine diesel engine that can no longer reach wide-open throttle — despite clean primary and secondary filters — likely has fuel restrictions elsewhere in the system.0:18 Nigel Calder identifies three additional choke points beyond the filters: a screen on the pickup tube inside the fuel tank, a ball or check valve on the primary filter inlet, and a filter screen inside the lift pump.1:05 He notes that the symptom appearing specifically at wide-open throttle confirms a fuel-starvation cause, since that is when fuel demand peaks.1:46 Dirty filters also signal a contaminated tank, and Calder stresses that tank cleaning is the root fix — not just filter replacement.0:42 Jan Attenstedt and Calder recommend inspecting every connection and restriction point throughout the entire fuel circuit.1:35 Both point to the marine diesel engine maintenance course at boathowto.com, which they describe as having its largest module dedicated to fuel hygiene, tank sampling, and keeping tanks clean on older boats.2:09

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