Aviation Engines Part 24

Crank Bearings. Adjusted too Overheating be- Adjust freely, clean Main Bearings. tight. Defective cause of friction. out oil holes and oiling. Bra.s.ses enlarge oil grooves.

burned. Oil Sump. Insufficient oil. Overheating. Replenish supply.

Poor lubricant. Use best oil. Wash Dirty oil. out with kerosene; put in clean oil.

Water s.p.a.ce. Water Clogged with sedi- Overheating. Dissolve foreign Pipes. ment or scale. matter and remove.

Piston Head. Cracked (rare). Loss of compres- Weld by autogenous Carbon deposits. sion. Preignition. process. Sc.r.a.pe off carbon acc.u.mula- tions.

NOISY OPERATION OF POWER PLANT

------------------+------------------+------------------+-------------------- PART AFFECTED NATURE OF TROUBLE CHARACTER OF REMEDY NOISE ------------------+------------------+------------------+-------------------- Compression Re- Leakage. Hissing. Previously given.

lease c.o.c.k. Spark Plug. Leakage. Hissing. Previously given.

Valve Chamber Cap. Leakage. Hiss or whistle. Previously given.

Combustion Carbon deposits. Knocking. Previously given.

Chamber. Inlet Valve Seat. Defects previously Popping in carbu- Previously given.

given. retor. Valve Head. Loose on stem. Clicking. Previously given.

Valve Stem. Valve Wear or looseness. Rattle or click- Previously given.

Stem Guide. ing. Inlet Valve. Closes too late. Blowback in carbu- Previously given.

Opens too early. retor. Valve Spring. Weak or broken. Blowback in carbu- Previously given.

retor. Cylinder Casting. Retaining bolts Sharp metallic Tighten bolts. Round loose. Piston knock. edges of piston strikes at upper top.

end. Cylinder Wall. Scored. Hissing. Previously given.

Valve Stem Too much. Clicking. Blowback Previously given.

Clearance. Too little (inlet in carburetor. valve). Valve Operating Looseness. Rattle or click- Previously given.

Plunger. Plunger ing. Guide. Timing Gears. Loose on fasten- Metallic knock. Previously given.

ings. Worn teeth. Rattle. Grinding. Cylinder or No oil, or poor Grinding. Repair oil system.

Piston. lubricant. Cam. Loose on shaft. Metallic knock. Previously given.

Worn contour. Cam-shaft Bearing. Looseness or wear. Slight knock. Previously given.

Cam Fastening. Looseness. Clicking. Previously given.

Piston. Binding in cylin- Grinding or dull Previously given.

der. Worn oval, squeak. Dull causes side slap hammering. in cylinder. Piston Head. Carbon deposits. Knocking. Previously given.

Piston Rings. Defective oiling. Squeaking. Hiss- Previously given.

Leakage. Binding ing. Grinding. in cylinder. Wrist-pin. Loose in piston. Dull metallic Replace with new Worn. knock. member.

Connecting Rod. Wear in upper Distinct knock. Adjust or replace.

bus.h.i.+ng. Wear at Sc.r.a.pe and fit. Use crank-pin. Side longer wrist-pin play in piston. bus.h.i.+ng.

Crank Bearings. Looseness. Exces- Metallic knock. Refit bearings.

sive end play. Intermittent Longer bus.h.i.+ngs Binding, fitted knock. Squeaking. needed. Insert s.h.i.+ms too tight. to allow more play.

Main Bearings. Looseness. Defec- Metallic knock. Fit bra.s.ses closer tive lubrication. Squeaking. to shaft. Clean out oil holes and grooves.

Connecting Rod Loose. Sharp knock. Tighten.

Bolts. Main Bearing Bolts. Crank-shaft. Defective oiling. Squeaking. Previously given.

Engine Base. Loose on frame. Sharp pounding. Tighten bolts.

Lower Half Crank- Bolts loose. Knocking. Tighten bolts.

case. Fly-wheel. Loose on crank- Very sharp knock. Tighten retention shaft. bolts or fit new keys.

Oil Sump. Oil level too low. Grinding and Replenish with best Poor lubricant. squeak in all cylinder oil.

bearings. Valve Plunger Re- Looseness. Clicking. Tighten nuts.

tention Stirrups. Fan. Blade loose. Blade Clicking or Tighten. Bend back.

strikes cooler. rattle. Exhaust Pipe Leakage. Sharp hissing. Tighten or use new Joints. gasket.

Crank-case Leakage. Blowing sound. Use new packing.

Packing. Tighten bolts.

Water Pipe. Leaks. Loss of Pounding because Previously given.

water. Clogged engine heats. with sediment. Water Jacket. Clogged with sedi- Knocking because Dissolve scale and ment. Walls engine heats. flush out water covered with s.p.a.ce with water scale. under pressure.

"SKIPPING" OR IRREGULAR OPERATION

------------------+------------------+------------------+-------------------- PART AFFECTED NATURE OF TROUBLE SYMPTOMS AND REMEDY EFFECTS ------------------+------------------+------------------+-------------------- Compression Relief Leak in threads or Dilutes mixture Screw down tighter.

c.o.c.k. spigot. with air, causes Grind spigot to seat blowback. with emery.

Spark-Plug. Leak in threads. Dilutes mixture. Screw down tighter.

Defective gasket. Allows short Replace with new.

Cracked insulator. circuit. No spark. Set points 1/64"

Points too near. apart for magneto, Points covered 1/32" for battery with carbon. Too spark.

much air gap. Valve Chamber Cap. Leak in threads. Dilutes mixture by Previously given.

Defective gasket. allowing air to enter cylinder on suction stroke. Combustion Carbon deposits. Preignition. Sc.r.a.pe out.

Chamber. Valve Head. Warped or pitted. Dilutes charge Previously given.

Loose on stem. with poor air or gas. Valve Stem. Binding in guide. Irregular valve Previously given.

Sticking. action. Valve Seat. Scored or warped. Gas leak, poor Previously given.

Cracked. Covered mixture. Poor com- with scale. Dirt pression. Valve under valve. will not close. Induction Pipe. Leak at joints. Mixture diluted Stop all leaks.

Crack or blowhole. with excess air. Inlet Valve. Closes too late. Blowback in carbu- Time properly.

Opens too early. retor. Exhaust Valve. Opens too late. Retention of burnt Time properly.

Closes too early. gas dilutes charge. Valve Stem Guide. Bent or carbon- Causes valve to Previously given.

ized. stick. Inlet Valve Stem Worn, stem loose. Air drawn in on Bush guide or use Guide. suction thins gas. new member.

Valve Spring. Weakened or Irregular action. Use new spring.

broken. Valve Stem Too little. Too Valve will not Adjust gap .009"

Clearance. much. shut. Valve opens inlet, .010"

late, closes exhaust.

early. Valve Spring Broken. Releases spring. Replace.

Collar Key. Cam. Worn cam contour. Valve lift re- Previously given.

Loose on shaft. duced. Does not Out of time. lift valve. Valves operate at wrong time. Cam-shaft Bearing. Looseness or wear. Valve timing Replace.

altered. Valve lift decreased. Cam-shaft. Twisted. Valves out of Previously given.

time. Cam Fastening. Worn or broken. Valve action Replace with new.

irregular. Valve Operating Loose in guide. Alters valve Replace with new.

Plunger. timing. Valve Plunger Wear in bore. Alters valve Replace or bush.

Guide. Loose on engine timing. Fasten securely.

base. Timing Gears. Not properly Valves out of Retime properly.

meshed. Loose on time. Valves do Fasten to shaft.

shaft. not operate. Piston. Walls scored. Leakage of gas. Smooth up if possible.

Piston Head. Carbon deposits. Cause premature Previously given.

Crack or blowhole ignition. (rare). Piston Rings. No spring. Loose Leakage weakens Previously given.

in grooves. Worn suction. or broken. Cylinder Wall. Scored by wrist- Gas leaks by. Poor Previously given.

pin. Scored by suction. lack of oil. ------------------+------------------+------------------+--------------------

IGNITION SYSTEM TROUBLES ONLY

_Motor Will Not Start or Starts Hard_

Loose Battery Terminal.

Magneto Ground Wire Shorted.

Magneto Defective (No Spark at Plugs).