1978 Johnson 175, 200, 235 HP Outboard Service Manual, Page 18Get this manual
TROUBLE CHECK CHART TROUBLE POSSIBLE CAUSE AFUEL SYSTEMSee Section Fuel line improperly connected Slow speed orifice blocked (or plug screw loose) Engine not primed Manual choke in "OFF" position Speed control not advanced (throttle closed) (warm up lever not in start position) Engine flooded Old fuel Clogged fuel filter screens Choke not operating Choke link broken or disconnected Fuel system faulty BIGNITION SYSTEMSee Section Timing, or linkage imprope ly adjusted Sheared flywheel key Loose wiring Ignition system faulty (key switch) Gear shift not in neutral Defective neutral start switch CELECTRICAL SYSTEMSee Section Wrong rotation (Bosch sta rter) brushes in wrong Starter circuit faulty 20 ampere fuse open or fuse holder damaged ranking speed too slow Key switch, wiring, or bad power pack APOWER HEADSee Section Carburetors and timer base not synchronized Throttle control lever (won't advance) Air leak at manifold gasketswarped manifold (backfires) Broken leaf valves (ba ckfires) Excessive carbon on pistons and cylinder head Stuck piston rings, or scored cylinder or piston BCARBURETORSee Section Old fueltoo much lubricant (dirt in carburetor) Spark advance stop rew loose Choke not operating properly Float valves and seats worn or stuck Incorrect carburetor float setting Incorrect orifice plugs Altitude horsepower loss Rich at idleidle bleed holes restricted Lean at high spe edpull-over jet restricted (235 hp only) FUE PUMP AND TANKSee Section Faulty fuel hose (cla mps or seals) (kinked) Fuel tank or pump filters plugged Fuel filters restricted Fuel and vent valves not opening Valves not operating Fuel hose passages restricted Incorrect fuel pumps Diaphragm leaking or damaged Antisiphon valves built in tanks incorrect or faulty DEXHAUST GAS ENTERING CARBURETORSee Section Exhaust cover screws leaking Damaged exhaust housing seals Adapter gaskets leaking racked exhaust housing Exhaust adapte to cylinder screws loose or missi ng