12343 Mercury SPARK PLUG (NGK #BP8HS-10) 6/8/9.9 H.P.

Fuel Injection Nozzles
Test/Exchange
Fuel injection nozzles are subject of tip wear. Tip wear, a result of fuel contamination, can cause:* increased fuel consumption* black smoke* misfire* rough runningNozzles should be cleaned, inspected, tested, and replaced if necessary. Refer to Special Instruction SEHS7292, for using the 8S-2245 Nozzle Cleaning Kit. Consult with your Caterpillar dealer about nozzle cleaning and testing.
Never wire brush or scrape a nozzle. Wire brushing or scraping a nozzle will damage the finely machined orifice. Proper tools for cleaning and testing nozzles can be obtained from authorized Caterpillar dealers.
Abnormal engine running, smoke emission, and engine knock can be symptoms of nozzle malfunction. Each nozzle must be isolated one at a time in order to determine the malfunctioning nozzle.1. Start the engine.
A nozzle will be damaged if the top of the nozzle turns in the body. The engine will be damaged if a defective nozzle is used because the fuel spray pattern that comes out of the nozzle will be incorrect. Nozzles can be permanently damaged by twisting if only one wrench is used to loosen or tighten the fuel line nuts. Do NOT let the tops of the nozzles turn when the fuel lines are loosened. Use one wrench to hold the nozzle and another to loosen the fuel line nut.
2. Loosen each fuel line nut at the fuel injection pump, one at a time. A cloth or similar material must be used to prevent fuel from spraying on the hot exhaust components. Tighten each nut before loosening the next nut.3. A defective nozzle may be identified when a fuel line nut is loosened and: * the exhaust smoking is partially or completely eliminated* engine performance is not affectedA nozzle suspected of being defective should be removed. A new nozzle should be installed in the cylinder to determine if the removed nozzle is defective.Removing and Installing Fuel Injection Nozzles
Special tooling is required to remove and install nozzles. Refer to the Service Manual for information. Consult with your Caterpillar dealer for assistance.Inspect, Rebuild, or Exchange
If the engine is operated until the components fail, additional engine damage can result. Caterpillar recommends that the following components be inspected in order to ensure reliable engine performance:* Jacket Water Pump* Raw/Sea Water Pump* Alternator* Starting Motor* Air Compressor Caterpillar RecommendationTo minimize downtime, Caterpillar recommends the use of Remanufactured components (subject to availability) as the most cost effective option. Removal and InstallationRefer to the Service Manual or contact your Caterpillar dealer for assistance with removal and installation of engine components.Water Pumps
A failed water pump might cause severe engine overheating problems that could result in cracks in the cylinder head, a piston seizure or other potential damage to the engine.Visually inspect the water pump for leaks. If leaking is observed, replace all seals. Refer to the service manual for the disassembly and assembly procedure.Inspect the component for wear, cracks, pin holes and proper operation. Refer to the service manual or consult with your Caterpillar dealer if repair or replacement is needed.Raw/Sea Water Pump
If the pump flow is reduced or if the pump can not self-prime, check for excessive wear of the impellers and the port plates. Refer to the Service Manual for the disassembly and assembly procedure. Rebuild or exchange the pump if necessary.Alternator
Caterpillar recommends a scheduled inspection of the alternator. Inspect the alternator for loose connections and proper battery charging. Inspect the ammeter gauge during engine operation to ensure the batteries and/or electrical system is performing correctly. Make repairs as necessary. Refer to the Service Manual.Check the alternator and battery charger for proper operation. If the batteries are properly charged, the ammeter reading should be very near zero. All batteries should be kept charged. The batteries should be kept warm because temperature affects the cranking power. If the battery is too cold, it will not crank the engine, even if the engine is warm. When the engine is not run for long periods of time or if the engine is run for short periods, the batteries may not fully charge. A battery with a low charge will freeze more easily than a battery with a full charge.Starting Motor
If the starting motor fails, the engine may not start in an emergency situation. Caterpillar recommends a scheduled inspection/check of your starting motor. The starting motor should be checked for correct operation.Clean and check all the electrical connections on electric starting motors. Check for air leaks at all the pipe connections on air starting motors. If repairs are needed, refer to the Service Manual, or contact your Caterpillar dealer for assistance.Air Compressor
Refer to the Service Manual or refer to the OEM literature for information concerning the air compressor. Contact your Caterpillar dealer for assistance.Turbocharger
Periodic inspection and cleaning is recommended for the turbocharger compressor housing (inlet side). Since the crankcase fumes are ingested through the inlet air system, oil and combustion by-products may collect in these two areas.This buildup, over time, can contribute to loss of engine power, increased black smoke, and overall loss of engine efficiency. This buildup is only a possible contributor to these conditions.Operating the engine until the turbocharger fails can severely damage the turbocharger's compressor wheel and/or the engine. Damage to the turbocharger compressor wheel could allow parts from the compressor wheel to enter the engine cylinder, causing additional damage to the piston, valve, and cylinder head.
Turbocharger bearing failures can cause large quantities of oil to enter the air intake and exhaust systems. Loss of engine lubricant can result in serious engine damage.Minor leakage of a turbocharger housing under extended low idle operation will not cause problems as long as a turbocharger bearing failure has NOT occurred.When a turbocharger bearing failure is accompanied by a significant engine performance loss (exhaust smoke or engine speed up at no load), DO NOT continue engine operation until the turbocharger is repaired or replaced.
An inspection/check of your turbocharger will minimize unscheduled downtime and reduce the chance for potential damage to other engine parts. Turbocharger components require precision clearances and balancing due to operation at high rotational (torsional)