gray marine vintage chris craft engine manuals 4 & 6 cyl

I Maintenance Manual Form No. 865

MAINTENANCE MANUAL GRAYMARINE GASOLINE ENGINES FOUR AND SIX CYLINDER MODELS Specifications for Current 9 and Non-Current Models Pages S-2 through S-15

Tab/e o f Conteots Page 1 Maintenance Instructions ........................ 3 Sta,iing Engine First Time ........................ 6 Operating Instructions. ......................... 8 Adjustments on New Engine .................... .lO Fuel and Fueling ................................ 10 Engine Installation ............................. .12 Water Piping Diagram .......................... 14 Fuel System ................................... 1 6 lubricating System. ........................... .20 Cooling System. .............................. .23 Electrical System. ............................. .30 Transmission. ................................ .43 Cylinder Head ................................. 5 5 Valves ........................................ 5 7 Timing ........................................ 6 0 Laying-Up Instructions ......................... .61 Starting’ Engine After Storage ................... .63 Trouble-Shooting Guide ........................ .65 Propeller Sizes, Average. ...................... .75 Condensed Specifications ............. .Center Section Condensed Adjustment Data .......... .Center Section Wiring Diagrams .................... .Center Section Engine Installation Data .............. .Center Section Gray Service Warranty ............... .Center Section

INTRODUCTION This pocket-sired hand book is supplied as a service to Gray owners. It is one evidence of our determination to make Gray service the most complete and useful in the industry. It covers both current models and older models. The scope of this manual is necessarily limited by its size but includes gasoline marine engine operating instructions, trouble shooting guide and directions for mak- ing simple adjustments to engine and accessories: such operations as can be done on the engine in the boat. Note that the section on “Installation” covers only such details as affect the care of the engine. The intent of the booklet is one of usefulness, and not to encourage tinkering. In the interest of good service, safety and long engine life the manufacturer recommends that major repairs can always best be done by experipnced marine service stations with a reputation for competent workmanship and a proper acceptance of the responsibility. Gray Marine Engine Division will be glad to recommend the nearest competent marine shop if your boat 1s not located near an authorized dealer. Also, remember that carburetors and electric accessories are made by com- panies with widespread service facilities; consult the classi- fied telephone directory. Important-When requesting information or when order- ing parts--b. sure to state Gxay Engine Model and Serial Nllmber. MAINTENANCE INSTRUCTIONS DAILY l Ventilate engine compartment thoroughly before starting engine. l Check pump flow by observing water and steam at exhaust outlet, each time engine is started. Do this at once. . Check lubricating oil level in crankcase (engine not running), and when necessary refill to high level mark on depth stick, using S.A.E. 30 oil. l At the same time, check oil level in hydraulic reverse gear. (This applies only to engines so equipped, when reverse gear has a separate oil supply.) Note: if oil needs to be added, look for a leak, because reverse gear normally consumes no oil. l Give grease cups on water pump one-half turn. Use water-proof grease. Do not over grease. EVERY 50 HOURS OF OPERATION l Inspect sea water strainer. l Check water level in battery. Proper fluid gravity is 1.275. l Put 3 to 5 drops of engine oil (S.A.E. 30) in the oiler on the outside of distributor body; or give grease cup one-half turn. depending on model. l Remove oil from crankcase, using Gray sump pump, and refill with fresh oil, S.A.E. 30, to high mark on oil depth gauge. Note: Before removing old oil. run the engine until it is thoroughly warm. l Put 3 or 4 drops of engine oil (SAX. 30) in oiler on generator, and two drops in oiler on cranking motor. (Some models have sealed bearings, so will have no oilers.) ONCE A MONTH l Inspect and clean Thermogard element. See page 27 l Clean sediment bowl on fuel pump. l Check adjustment of clutch and reverse gear. See pages 43 to 52 for directions. l Inspect flame arrester to make sure the air passages are clean and free from oil or lint. If dirty, remove and wash in mineral spiriti.

?ope 4 Graytnahe Gasolrire Engines EVERY 150 HOURS 0 Replace cartridge in lubricating oil filter, if engine is so equipped. l Apply one drop only of light engine oil (S.A.E. 10) to the breaker arm hinge pin in distributor. l Givegrease cup on tachometer drive one turn. (Applies only to right angle type mounted on cylinder head.) l Remove the distributor rotor and apply 3 to 5 drops of light engine oil (S.A.E. 10) to the felt in the top of the breaker cam and to the governor weight pivots. TWICE A SEASON “TUNE UP” l Clean the engine thoroughly. . Check distributor setting. See page 39. l Check carburetor adjustment. See page 18. l Check engine coupling for misalignment. Tighten lag bolts holding engine to bed. l Check valve tappet adjustment. For correct clearance, see pages S-3, S-4, S-13 and S-15. in center section. l Chock grease in drive gear housing of double gear type water pumps. Add bearing grease (EQ-2095) if required. 0 Remove the distributor head and smear a bit of grease the size of a match head on the lobes of the breaker cam. 0 Clean and adjust breaker points on distributor. Points should contact evenly, and gap must not exceed .020” or condenser can be burned out. See page 37. l Check spark plugs and set gap, using a round wire feeler gauge. Clean fouled plugs and ooarch for cause of fouling. Replace crocked or doubtful plugs. Use plugs of correct heat range. KEEP A SERVICE LOG Maintenance lnstmctions l Inspect all wiring for loose connections or worn insulation. Clean battery terminals with soda solution and coat lightly with Vaseline or grease after connection is made. EVERY 1000 HOURS OR ONCE A SEASON l Change oil in hydraulic reverse gear if engine is so equipped. Use Automatic Transmission Oil Type “A”, Suffix “A”, (SAE 30 engine oil may be used only in an emergency.) IM- PORTANT: after running engine briefly in both forward and reverse, stop engine and recheck transmission oil level. See page 52. l Grind and adjust valves. l Check valve stems for carbon. a Give engine a thorough going-over. 0 Clean Oil Cooler. l Clean commutator on generator, using No. 00 sandpaper. Do not use emery cloth. l Ii compression is weak, look for imperfectly seating valves or rings stuck in groove* on piston. EVERY 2500 HOURS l Time for a major overhaul. l Install new piston rings. Check piston clearance. l Check bearings. When oil presmure drops below 20 pounds, this ia an indication of worn bearings.

Graymarhe Gasohe bghes INSTRUCTIONS ON STARTING ENGINE FIRST TIME BEFORE STARTING THE ENGINE After the engine has been properly installed ond all controls properly connected. the following instructions are to be carried out before starting a new engine: 1. Check Fuel Supply: Be sure the tank is clean, then fill with a good grade of gasoline. Refer to page S-2 in center section for fuel recommendation. Some models require premium ethyl. 2. Check Lubricating Oil in Crankcase: Engine is shipped dry from factory with oil drained from the crankcane. Do not fail to check oil level. Fill to the high level notch on oil depth gauge, using a good grade of oil, S.A.E. viscosity No. 30. Lift oil depth gauge during filling to permit escape of air. Note: If engine is equipped with hydraulic reverse gear, check oil depth stick on transmission for separate oil supply, using Automatic Transmission Oil, Type “A”, Suffix “A”. 3. Check Lag Bolts holding engine to bed: must be tight. IMPORTANT: If the boat came off a train or truck, or if it has been out of the water for considerable time, check the shaft alignment. (Instructions on page 16.) 4. Inspect the Engine for loose nuts or screws. Transpor- tation frequently loosens fastenings on a new engine, on account of gasket shrinkage. After engine has had a preliminary run, take up on cylinder head nuts. See p. 56 5. Check Storage Battery: Make sure that storage battery is filled, with water level at least 3,s” above the plates, and fully charged. Proper fluid gravity is 1.275. Low battery will result in slow cranking speed and weak spark. 6. Check All Electrical Connections including battery cables. Make sure they are tight, and all connections soldered. (Use rosin flux in soldering.) 7. Check Water Circulation System: Open the gate valve on the cooling water intake line. This valve should be located in the bottom of the boat. Caution: if water pump is rubber impeller type, it must be primed at first start of the season. 6. Check All Controls to make sure they are working freely with sufficient travel so that they do not strike against woodwork. This refers to choke, throttle and rover*8 controls. ODefatiirp lnZrruction.5 9. Safety Precautions: Check engine compartment and bilge for gasoline fumes. If boat is equipped with ventilating fan, run it for 5 minutes before starting; otherwise open hatch or engine box and let dead air out. 10. Turn on the Gasoline: The shut-off cock is properly located near the fuel tank. 11 12. 1. 2. 3. 4. Fig. l--Fuel Pump Primer Fill Carburetor: Use hand primer on fuel pump (Fig. 2 to fill sediment bowl and carburetor. (Note: on some small engines fuel pump does not have hand primer. Ppt Clutch in Neutral. HOW TO START THE ENGINE Set the Throttle above idling position, about I4 open. Pull Out the Choke: Keep your hand on it for quick adjustment as soon as the engine starts. A marine engine, particularly if it has two carburetors. needs plenty of choke to start. Turn on Ignition Switch. Press Starter Button. CAUTION: Do not operate cranking motor longer than 30 8eCOAdI. A longer period than 30 recondr may damage the rolenoid awitch and cranking motor. If l agiae does not 8tart, refer to detailed instructions OA Page 65.

hp. 8 Graymarine Gasoline Engines NOTE: Engines which have been in transit and storage for a period of weeks may start hard the first time. In such case, remove spark plugs and clean the electrodes. While the plugs are out, put a tablespoonful (no more) of light oil, SAE 10. in each cylinder to provide an initial oil seal between piston rings and cylinder walls. Memo on Flooding: If you flood the engine by too much choking, the correct way to dry it out is to open the throttle wide. Put the choke in the running or non-choking position. Then with ignition on, crank the engine a half dozen times. This draws nothing but air through the carburetor, as the idling jet is out of action at full throttle, and the engine does not revolve fast enough for the main jet to go into action. OPERATING INSTRUCTIONS 1. To Drive the Boat Forward push operating lever forward until it snaps into a locked position. 2. To Reverre, pull lever back as far as it will go. Reduce speed before shifting. CAUTION: The engine must not be operated unless the cooling water is circulating. See instructions below. Fig. 3- Gray D&nca Inrlrunren~ Panel 77800 (12~) or 75650 (6~) with Tachometer, Operating Hours Register, Oil Temperature Gauge, and Ammeter fpanel calibrated of 1796 rpm) AFTER THE ENGINE STARTS Check Oil Pressure Gauge: Normal oil pressure at operating speeds is 30-40 pounds. An oil pressure 01 less than 20 pounds calls for investigation (5 to 15 pounds is satisfactory at idle). NOTE: Gauge may show no pressure for a minute or two while the filter ir filling with oil. Operating Instructions Pago 9 2. CheckSoaWoterPnmp.Circulationshouldbeginwithin a half minute aftor engino is started. On Thermogard- equipped models. only a small amount of water muffi- cient to cool the tailpipe will be expelled, the rest of the water being recirculated until engine warms up. Neoprene Impellorr are lubricated by the flow of water. Consequently, never operate a dry pump. Always prime pump if it haa become dry after draining or extended idleness. On bronze gear pumpa (used on smaller four-cylinder engines) the prime of pump is assisted by sufficient grease sealing the impellers. If pump does not operate immediately, turn grease cup down yz turn. NOTE: Pictures of these units shown on Pages 24, 25. CAUTION : (Applies only to bronze gear pump) : If boat t run in muddy woterm, the water pump should be rcmovcd and all old grease in impeller housing thoroughly cleaned out at froquont intervals. Silt which entered the pump will mix with the geam and act aa a grinding compound. Thir can caume exceptionally rapid wear on metal parts. 3. The first time the engine is started, run it at idle for 5 minutes, no longer, then stop engine and recheck oil level in crankcase, and in reverse gear housing when applicable. (Do not check oil level while engine is running.) Oil level may be found low due to the fact that considerable oil is required to fill the oil passages: or it may be found high if depth gauge was not removed for venting air during the initial filling. Bring oil level to high mark on depth gauge. 4. Warm-up Iastructfoas: (To be followed every time you start a cold engine.) As soon as possible put the clutch lever in forward position and run at fast idle for 10 to 15 minutes. in order to bring the oil up to proper temperature for full throttle work. An indication of warm oil is that the oil pressure will drop off about 5 pounds from what it was when engine was cold. IMPORTANT: Do not under any circumstances race the engine with clutch disengaged. FULL THROTTLE OPERATION 1. Recheck the Oil Preuwe a soon W you try out the boat at full speed. If indicating needle on the oil pressure gauge fluctuates wildly, this will indicate either a leak in the oil line, or that the angle of the engine is such that oil pick-up screen ia not completely submerged. The remedy for this in to stop engine and add more oil. See Fig. 10, page 21. for an understanding of the relationship between pick-up screen and oil level.

?ega 10 Graymarine Gasoline Enghes 2. RadPce Engine Speed When Reversing: Gear should not be reversed at full engine speed except in extreme emergency. 3. Although all Graymarine engines ara thoroughly tested at the factory, good judgment is expected on the warm-up and operation during the early life of the engine. It takes from fifteen to twenty hours run- in to break in an engine for peak performance. On high speed models, oil consumption will be more until the piston rings fit themselves perfectly inside cylinder walls, after a few hours of fast operation. ADJUSTMENTS ON A NEW ENGINE 1. Propeller Shaft Alignment: If the boat is new. be sure to check the alignment within a few days, after the hull has soaked up some water, because the hull is liable to change its shape slightly, especially when loaded, resulting in binding on the shaft. 2. Carburetors: Careful adjustment is made in the test room. Never re-adjust carburetor unless engine is warm and under full load. Make sure that control ex- tensions permit full travel of throttle and choke levers. 3. Clutch Adjustment: After the first few hours of operation examine the adjustment of manual gear. Clutch lever should stay in either position without being held. It should snap into the forward position and shouldstay in reverse without forcing. (NOTE : This does not apply to some four-cylinder models which have wedge mech- anism for reverse position, and must be held in reverse.) For instructions on clutch adjustment, see pages 45 to 52. Wanting: Never operate engine with loose and slipping clutch, because this condition will generate heat by friction, warping and galling the clutch plates, causing permanent damage. Clutch trouble is nearly always due to negligence. 4. After first 10 hours of operation, have the valve tappets readjusted to specified clearance (see center section) by a competent marine service station. This is your responsibihty. 5. Valve Sticking: Sometime5 valve5 on new engine5 or those which have been in storage tend to stick. See page 59 for remedy. FUEL The Gray Marine Motor Company approve5 the use of high grade gasolines as marketed by reputable refiners. Good, fresh gasoline of the correct octane for the particular model engine should be used; the correct grade for each model Opefating hstfucth Pm00 11 is shown in the data section for current models (page S-2) on tinted paper at center of book. Good gasolines are processed against gum forming tendencies even whon subjected to long time storage. Some gasolines form gum deposits rather quickly; these deposits appear as a jelly- like coating within the copper fuel tanks; they are also observed as a whitish precipitate in the fuel lines, also in carburetor float bowls and jets, which deposits impair or restrict fuel flow. This gum-forming tendency with at- tendant deposit can also contribute to impaired operation of engtne intake valves. Where the boat is to be out of commission for 30 days or more. drain the fuel tanks, fuel linem, fuel pump and the carburetor as a precaution against possible gum forming deposits within these parts. Use good gasolino muppliod by a reputable fuel marketer, a gasolino of the required octane value am prescribed for your Graymarine engine. On brand new steel tanks, the first fill of gasoline will often carry off rust-inhibitor coatings, flux and other matter which will bo detrimental to the carburetor. Thorofore, we suggest the addition of a solvent such as Siloo, Casito, or equivalent, in new tanks. MOTORBOAT FUELING INSTRUCTIONS (Issued by the United Staterr Court Guard) 1. Fuel tanks should be properly installed and vonted. 2. Fueling should be completed before dark except in l mergenciu. 3. Whenover boat is moored at service l tation for fueling: (a) Do not mmoke. strike matches, or throw switchem. (b) Stop all engines, motors, fans, and dovices liable to produce mparkm. (c) Put out all lights and galley fires. 4. Before mtarting to fuel: (a) See that boat is moored securely. (b) Close all ports. windows, doors and hatohr. (c) Aaoertain dofinitoly how much additional fuel the tanks will hold. 5. During fueling : (a) Keep nosxlo of hose or can in contact with fill opening to guard againmt ponible static spark. (b) See that no fuel spills got into hull or bilges. 6. After fumling is completed : (a) Close El1 openingm. (b) Wipe up a11 spilled fuel. (c) Open all ports, windows, doors and hatches. (d) Permit boat to ventilate for at least 5 minutes. (e) See that there is no odor of gasoline in the l ngtne room or below decks beforo l tartfng machinq or lighting fire. (f) Be prepared to cast off moorings as soon a engine l tartm.

rag* 12 G faymarhe Gasohe Engines ENGINE INSTALLATION Proper installation is a condition of the Gray Warranty. This brief section is included to give emphasis to some essential details, because a high percentage of service troubles are caused by faulty installation. 1. Moving tie Engine: The engine is fitted with either one or two lifting rings designed to carry the full weight of the engine, therefore auxiliary slings are not required or desired. Never try to so ely, and may damage accessories. P ut a sling around the engine, as this will not hold the engine 2. Engine Bedr This should always be of sufficiently heavy section to insure rigidity, and well secured to the hull. Maximum operating angle of the engine at full speed, as mounted on this bed should not exceed 16 degrees from water level, because at a higher angle the lubricating oil pick-up screen may not be fully submerged (see Fig. 10, page 21). Remember that the angle may increase if the boat is loaded deeply at the stern and the bow is light and high. 3. Exkaurt Piping: This must never be reduced in sire at any point smaller than the flange size supplied on exhaust manifold. It may be increased in sise. Use standard pipe and fittings only, or tubing of equal or larger inside diameter than the correspond- ing iron pipe sire. Do not use “street ells” for connections (see pig. 5). No bends should be more than 45”, and all exhaust exits must be above water line. For most installations, all of the dis- charged cooling water can be carried by the tailpipe., Water MUST enter exhaust pipe at a point lower than exhaust manifold, preferably 6 to 8 inches from flange, so that there will be no danger of any water getting back through the exhaust valves, regardless of boat’s pitch. Water stream should enter exhaust flow diagonally; not at right angle. We recommend the use of a Graymarine water-cooled elbow at this point, available in sizes to fit all engine models. (See diagram next page). 4. Watox Piping: Use standard pipe and fittings only, eltm- inattng all “street ells” which impose a restriction on the flow (refer to Fig. 5). Connect sections with hose over pipe and hose clamps for vibration joints. IMPORTANT: Intake piping to water pump should never be smaller than the I.P.S. of intake fitting on pump. We recommend using nest pipe size larger than intake of pump for free flow. Avoid sharp bends. 5. Water Intake Scoop: Through-hull fitting should always be one size larger than the pump intake sire. Locate the scoop so that the intake pipe to pump will be as short and straight as possible. Bends reduce flow and add to load on pump. 6. Soa Cock: A gate valve in water intake pipe is desirable but not essential. It must be of free tlow type and of sufficient sise to prevent any restriction to flow. 7. Check Valve in Water Intake Line: When this is an item of the installation use valve one size larger than intake pipe sise, reducing to intake pipe size with bushings, to provide adequate flow area. 8. Water Recixculation Line: All current models of engines up to and including those with piston displacement of 226 cu. in. use a dual unit Thermogard temperature control system with choke-type thermostat at the outlet to overflow line, and a pressure valve at the outlet for the recirculation line, piping for which is shown in Fig. 4h. Larger engines use a single unit Thermogard valve, shown in Fig. 17, to be piped as shown in Fig. 5. In both types note that the T-fitting for recirculation line MUST be located below the load-water-line of boat. It is important that no restrictions of any kind exist in the recirculation line or the overflow line. Neither must be smaller than pump intake size.

Pmp. 14 Graymarrie Gasolrire E&/ires Ffg. 5-Pbfng Diagram with ‘Thermogord”. Pipe Size “A’‘-not smollw thwa pump intake size. Pfpo Size ‘W-one sfza larger then pump sire. 9. Fresh Water Cooling System: For engines with this equip- ment, we insist upon use of a heat exchanger unit approved for adequate size and proper design. Units supplied by Gray Marine Motor Company will give perfect service because they are en- gineered to fit the engine. CAUTION: Remove W” pipe plug vent, in pump-to-manifold pipe, when filling the system with coolant. See pages 23-30. 10. Fuel Tubing: Size must not be smaller than the size indicated by the tube nut on fuel pump fitting supplied with engine. A flexible section of sufficient size is desirable between the fuel line and fuel pump, or a loop in the tubing may be provided to prevent breakage due to vibration and strains. Note: On twin engine installations, if you do not have two gas tanks, be sure to run a separate line from the tank to each engine-not through a header line. 11. Oil Prerrure Tube to oil pressure gauge on instrument panel is connected to a brass fitting on carburetor side of cylinder block. Use W” tubing, anchored with tape to prevent chafing, and with a loop in the tubing at engine end to prevent metal fatigue from normal engine movement. On rubber mounted engines, use flexible tubing or a flexible section at engine end. 1 A NGLE M OUNTING I H ORIZONTAL MOUNTING- I -for installation on sloping engino beds, as shown here using solid mounts and aligning shims in Q typical auxiliary. Similar condffions in many crvisws. Fig. 6-Fnginm Mounts 12. Therm0 Switch (supplied with Instrument Panels #75650, z.77800. To mstall this, remove pipe plug from J 5” I.P.S. threaded hole at front end of cylinder head. Insert thermo-switch element, and connect with smgle wire to instrument panel. See Wiring Diagram, page S-6. 13. Tachometer Cable (supplied only with instrument panel). Connect from instrument panel to fitting on side of reverse gear housing on most models. Note: on some models this connection is located in center of cylinder head. 14. Electrical Connections: Follow wiring diagram to conform to type of generator on engine (pgs. S-6-S-1 1) and use wire sizes no smaller than those ‘indicated. Solder all connections. Locate battery as close to engine as possible, with short cable, not smaller than No. 0. For ground connections, see page S-5. 15. Voltage Regulator (supplied for engines with constant- voltage generator.) This should conform to ground polarity (see page S-5). After wiring is completed, repolarize the generator (instructions are on page S-8). NEVER polarize an alternator. 16. Propeller Size: Final selection of propeller should be size which will permit the engine to turn close to its maximum rated rpm. Tables of suggested propeller sizes are on pages 74-75.

gray marine vintage chris craft engine manuals 4 & 6 cyl

You're Reading a Preview

Recently Viewed