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LARSON Boat Troubleshooting

LARSON Boats Troubleshooting Guide  

Engine will not crank (Ignition system)

1.Throttle lever in wrong position


2.Loose wire in starting circuit


3. Ignition switch defective


4. Defective solenoid


5. Battery switch in OFF position


6. Dead battery


7. Spark plug(s) fouled or broken


8. Distributor cap broken, wet, cracked,or dirty


9. Hydrostatic lock

1.Check position of throttle lever, ensureit's in the NEUTRAL position.


2.Tighten all wiring connections


3. Test switch continuity. Replace switchas required.

4. Replace solenoid.


5. Turn dual battery switch to battery set-ting #1 or #2; if equipped


6. Recharge or replace battery


7. Clean, adjust gap, or replace


8. If wet or dirty, wipe with cloth andcleaning solvent.

Inspect cap forcracks, carbonized paths (inside andout); replace cap as required


9. Remove spark plugs and crank engine.

If engine cranks water is entering cylin-ders from exhaust system, or from apossible gasket leak.

If water entersengine through exhaust line, improperdraining of exhaust system exists.

Contact your Larson dealer or a qualifiedmarine mechanic to correct problem

Engine cranks but will not start

1. Lack of fuel


2. Improper starting procedure


3. Choke plate sticking


4. Clogged fuel filter


5. No fuel reaching carburetor (providingall fuel valves are open)


6. Engine flooded


7. Contaminated fuelIgnition interrupter switch


8. Ignition interrupter switch

1. Clean fuel filter, check fuel level, andcheck anti-siphon valve


2. See your engine manual to reviewstarting procedure


3. Check thermostatic spring housingadjustment


4. Check fuel filter, replace if required


5. Check fuel pump, fuel pump filter, car-buretor fuel filter, and fuel tank line forcracked flanges or restricted fittings,check anti-siphon valve


6. Do not attempt to start engine for atleast 5 minutes. For hot engine, fully advance throttle once, return throttle to NEUTRAL then crank engine


7. Inspect for water or other contaminantsin fuel. If contaminated, drain tank andflush with fresh fuel

8. Connect lanyard to switch and driver

LARSON Boat Troubleshooting Guide

Low cranking speed

1. Loose or dirty electrical connections ordamaged wiring


2. Bad battery


3. Engine oil too heavy for current temperature

1. Check all related electrical connections and wires


2. Test battery (See your engine manual)


3. Drain oil and refill with correct gradeand viscosity oil (See your enginemanual)

Starter will not crank engine

1. Discharged battery


2. Corroded battery cables


3. Loose connection in starting circuit


4. Defective starter switch


5. Starter motor brushes dirty


6. Jammed starter drive

1. Charge battery, change dual batteryswitch to ALL; if equipped

2. Clean terminal


3. Check and tighten all connection


4. Replace switc


5. Clean or replace brushes


6. Loosen starter motor, then free lockedgear

Poor acceleration

1. Accelerating pump


2. Throttle not fully open


3. Ignition or carburetor


4. Flame arrestor dirty or air intake obstructed


5. Engine overheating

1. Replace.


2. Inspect cable and linkages for binding,obstructions, or loose fasteners.


3. Service ignition system and carburetor.


4. Clean flame arrestor and check airintake.


5. Check engine temperature (See your engine manual

Engine runs but misfiring

1. Fouled spark plug(s)


2. Improper timing


3. Wet spark plug wires


4. Carbon tracked distributor


5. Loose ignition wires


6. Cold engine with improperly set choke


7. Defective fuel pump


8. Partially clogged fuel filter


9. Incorrect carburetor mixture


10. Contaminated fuel

1. Remove and clean, replace asrequired


2. Check timing and adjust as required (See your engine manual


3. Inspect wires, wipe dry, replace damaged wire


4. Clean, replace as required


5. Inspect all wire connection


6. Check your engine manual for properchoke setting


7. Repair, replace as required


8. Clean fuel filter, replace as require


9. See your engine manual for proper carburetor adjustmen

10. Drain fuel tank and flush clean; replacefuel filter

Excessive fuel consumption

1. Restriction in flame arrestor


2. Faulty fuel pump


3. Dirty flame arrestor screen


4. Distributor breaker points or sparkplugs improperly set or bad


5. Incorrect timing


6. Choke not properly adjusted


7. Float level too high

1. Remove and clean flame arrestor.


2. Repair, replace as required.


3. Clean, replace as required.


4. Clean, set or replace breaker pointsand spark plugs.


5. Time engine


6. Adjust choke as required.


7. Reset float level as required (See your engine manual)

LARSON Boat Troubleshooting Guide

Blue exhaust smoke

1. Lube level too high


2. Oil too thin


3. Oil overheated

1. Drain off excessive oil.


2. Drain and replace oil (See your enginemanual).


3. Check cooling system

Black or gray exhaust smoke

1. Fuel mixture too rich


2. Choke locked


3. Poor carburetor setting


4. Carburetor fuel level too high


5. Clogged flame arresto

1. Adjust carburetor.


2. Lubricate and adjust.


3. Readjust carburetor (See your enginemanual).


4. Adjust carburetor float.


5. Clean, replace as require

White exhaust smoke

1. Engine misfiring


2. Spark plugs dirty or not gappedcorrectly


3. Engine overheating

1. See your engine manual.


2. Clean, adjust gap, replace as required

Low oil pressure

1. Insufficient oil in crankcase


2. Excessive oil in crankcase


3. Diluted or improper grade andviscosity oil


4. Oil leak in pressure line

1. Check and add correct grade andviscosity oil. Visually check engine forleaks


2. Check and remove any excess amountof oil. Check for cause of excessive oil(improper filling, bad fuel pump, etc.)


3. Change oil and oil filter, using thecorrect grade and viscosity oil


4. Inspect all oil lines and tighten allconnections as necessary