Flame Arrestor 7.4L and 8.1L MPI | Crusader Marine R145021

Flame arrestor from Crusader for MPI model engines including the 7.4L and 8.1L engines with 3 3/4 inch mechanical throttle body.

Crusader Flame Arrestor 7.4L and 8.1L MPI | R145021

• Flame arrestor for various multiport fuel injected engines
• Clamps to throttle body air horn
• Used on 7.4L and 8.1L model engines with mechanical throttle body
• Can replace obsolete 49037 and R145023 in some applications
• Measures 9 3/4 inches long, 5 3/8 inches wide and 3 1/2 inches deep including the clamping collar
• Fits 3 3/4" throttle body airhorn

Frequent Asked Questions 

With today’s rising gasoline prices, what octane rating is recommended for Crusader engines?

Crusader fuel injected engines are calibrated to operate on 87 octane fuel and maximum performance is obtained when using this fuel. The ignition timing set by the factory requires the use of a high-quality lead free regular gasoline with an octane specification of (R+M/2).

‏What kind of oil should be used in Crusader engines?

When the average temperature is above 50 degrees F., use a good quality SAE 15W-40 “SJ”. Below 50, use SAE 5W-30 “SJ”

Synthetic oils are not recommended for use in Crusader engines. 

What is Crusader's policy on the use of Ethanol?

This notification addresses the use of ethanol fuels IN CRUSADER ENGINES ONLY. It does not address the use of ethanol fuels in vessel related components such as boat gas tanks, boat fuel lines, boat fuel filters, etc. The boat owner is STRONGLY ENCOURAGED to contact the boat builder regarding the suitability of ethanol fuel usage in their vessel.

Ethanol blended fuel rated E10 or less is acceptable to use.

Fuels rated higher than E10 SHOULD NOT BE USED.

Ethanol fuels rated higher than E10 could potentially damage the engine and/or present an unsafe boating condition. Damage to the engine resulting from the use of ethanol fuel rated higher than E10 is not covered by the warranty.

What type of coolant should be used in Crusader engines?

Crusader recommends DEX-COOL or any good extended life coolant (pink/orange in color) mixed 50% DEX-COOL to 50% water for engines that have a closed cooling system. More than 50% coolant can contribute to overheating. Do not mix or substitute DEX-COOL with traditional silicated coolant (green in color).