Service Manual 25-30 HP E-TEC Powerhead [Powerhead Assembly]

Proceed slowly. Make no forced assemblies unless a pressing operation is called for. All internal components must be perfectly clean and lightly coated with outboard lubricant.

Use new wrist pin retaining rings, gaskets, seals, and O-rings during assembly.

Crankshaft Assembly

Oil the end of the crankshaft. Use Crankshaft Bearing/Sleeve Installer, P/N 339749, and place a new lower main bearing onto crankshaft with lettered side facing the tool. Install bearing until it seats on the crankshaft.

Oil the end of the crankshaft. Use Crankshaft Bearing/Sleeve Installer, P/N 339749, to drive a new sleeve onto the crankshaft until the installer contacts the lower main bearing.

If the installer sticks on the sleeve after installation, thread Slide Hammer, P/N 391008, into installer and pull it off.

Inspect sleeve after installation.
Sleeve must not be used if surface is damaged.

Use retaining ring pliers to install bearing retaining ring with sharp edge facing away from bearing.

Lubricate a new driveshaft O-ring and lightly lubricate crankshaft splines with Moly Lube. Install O-ring in sleeve.

1. Bearing retaining ring
2. O-ring

Lightly coat the outside edge of a new lower housing seal with Gasket Sealing Compound. Press against outer case of the seal to install seal in the lower housing with extended lip facing down. Lubricate seal lip with Moly Lube.

1. Seal lip

Install a new O-ring on the lower housing. Before installing crankshaft into cylinder block, apply a thin coat of Gasket Sealing Compound to outer edge of O-ring.

Place lower seal housing on crankshaft.

1. Lower seal housing
2. O-ring

Lubricate upper main bearing with outboard lubricant and install on crankshaft.

1. Upper main bearing

Pack lip of upper oil seal with Moly Lube. Place seal on crankshaft with lip toward driveshaft and enclosed face toward flywheel. Do not apply sealer to outside edge of the seal.

1. Upper oil seal

Pistons and Connecting Rods

It is very important that the pistons in this engine are installed in the correct location and direction.

New pistons are stamped “UP.” This marking should be turned toward the top of the crankshaft.

1. Stamped marking

Apply outboard lubricant to the wrist pin bearings, wrist pin and wrist pin bore. Install the bearings in the small end of the connecting rod.

1. Wrist pin bearings

Place the piston over the connecting rod and bearings.

Install wrist pin through piston and connecting rod.

Use Wrist Pin Retainer Installation Tool, P/N 354720, to install new wrist pin retaining rings in each wrist pin hole. Place one retaining ring into tool base. Insert driver into base and through retaining ring. Align tool on piston. Support piston and tool. To seat retaining ring, swiftly strike the driver.

Gap of retaining ring faces up, away from notch in piston.

1. Gap of retaining ring
2. Notch in piston

Installing Pistons

When all pistons and connecting rods are assembled, install piston ring sets. Be sure rings are installed in the cylinder used to test ring end gap. Refer to POWERHEAD INSPECTION on p. 203.

Be sure gap of ring fits squarely around dowel pin.

Before continuing, make sure that all Gel-Seal II has been removed from the cylinder block and crankcase mating flanges. If traces of hardened Gel-Seal II are left, main bearings could be misaligned. Refer to CYLINDER BLOCK CLEANING on p. 202.

Crankshaft Assembly Installation

Rotate cylinder block so crankcase mating flange is facing up.

Apply Gasket Sealing Compound to lower oil seal groove in cylinder block. DO NOT put any sealer in upper seal groove.

Coat pistons, rings and cylinder walls with outboard lubricant.

Locate piston rings on dowel pins.

Carefully lower crankshaft assembly into the cylinder block.

• Align tab on lower bearing seal housing with slot in crankcase.
• Align upper oil seal in groove.
• Locate center and upper main bearing dowel pin with slot in crankcase.

1. Lower bearing seal housing tab and slot
2. Center and upper main bearing dowel pin and slots

Crankcase Assembly

Thoroughly clean and degrease the mating flanges of the crankcase and cylinder block with a non-petroleum based solvent, such as isopropyl alcohol or acetone, and let air dry.

DO NOT allow solvent to get on internal components. Clean only the mating flanges.

Apply Gasket Sealing Compound to lower oil seal groove in crankcase. DO NOT put any sealer in upper seal groove.

Use a small brush with a tapping motion to apply a thin, even coat of Gel-Seal II sealant to the crank case mating flange. The sealer must not come within 1/4 in. (6.4 mm) of bearings.

TYPICAL

Gel-Seal II has a shelf life of at least one year when stored at room temperature. Test the Gel-Seal II or replace it if the age of the tube cannot be determined. Using old Gel-Seal II could cause crankcase air leaks.

The use of Locquic Primer is NOT recommended. If primer is used, crankcase halves must be assembled and tightened within ten minutes after the Gel-Seal II has been applied.

Lower the crankcase into place. Make sure that upper oil seal and lower seal housing are seated in grooves.

Apply outboard lubricant to the main bearing screws. Tighten main bearing screws in stages to a final torque of:

• 10 to 12 ft. lbs. (14.5 to 16.5 N-m).

Start in the center and work outward in a spiral pattern.

Apply Nut Lock to crankcase flange screws. Install crankcase flange screws and tighten to a torque of 84 to 106 in. lbs. (9.5 to 12 N-m).

Test that the crankshaft spins freely without binding.

After powerhead has been assembled, allow at least two hours for Gel-Seal II to cure before running outboard.

Apply Gasket Sealing Compound to both sides of new inner and outer exhaust cover gaskets. Position gaskets and covers on cylinder block.

1. Inner exhaust cover
2. Outer exhaust cover

Apply Nut Lock to cover screws. Tighten all screws in sequence, to a torque of 84 to 106 in. lbs. (9.5 to 12 N-m).

Cylinder Head Installation

Apply soapy water to water dam and insert into block.

1. Water dam tab

Place a new cylinder head gasket on alignment pins.

1. Alignment pins

Install cylinder head with the thermostat toward the top. Apply Triple-Guard grease to the threads and install the cylinder head screws. DO NOT use any sealant on threads

Following sequence on cylinder head, tighten all screws in stages to a torque of 10 to 12 ft. lbs. (14.5 to 16.5 N-m)

1. Cylinder head screws (10 total)

Megaphone and Inner Exhaust Housing Installation

Install water plug in cylinder block as shown.

1. Water plug

Place a new gasket on the powerhead. Apply Nut Lock to screws. Install exhaust megaphone and secure with three screws. Tighten screws to a torque of 84 to 106 in. lbs. (9.5 to 12 N-m).

1. Screws

Apply Nut Lock to screws. Install inner exhaust housing and secure with five screws. Tighten screws to a torque of 84 to 106 in. lbs (9.5 to 12 N-m).

1. Screws

Shift Linkage Installation

Place the spring, guide, and ball of the shift detent assembly into the crankcase. Lubricate with Triple-Guard grease.

1. Shift detent assembly

Lubricate shift linkage bosses at the base of the cylinder block with Triple-Guard grease. Insert bushings into bosses.

Apply Triple-Guard grease to the shift lever and shaft assembly. Guide shaft through bushings in crankcase.

Shift lever and shaft must be positioned with pin toward the rear of the cylinder block.

1. Bushings
2. Shift lever and shaft assembly
3. Pin

Install shift lever and detent on shaft assembly. Install nut and tighten nut to a torque of 84 to 106 in. lbs. (9.5 to 12 N-m).

1. Nut

Be sure the shift rod connector is fully seated. Install the shift shaft on the pin and secure with clip.

1. Shift shaft
2. Clip

Throttle Linkage Installation

Apply Nut Lock to threads of throttle lever screw.

Insert spring into cavity of throttle return lever.

Install lever, screw, and washer on crankcase and hook spring on rib as shown. Tighten screw to a torque of 120 to 144 in. lbs. (13.5 to 16 N-m).

1. Hook spring here

Apply Nut Lock to threads of throttle cam screw.
Install cam, screw, and washer on cylinder block and tighten screw to a torque of 120 to 144 in. lbs. (13.5 to 16 N-m).

1. Throttle cam screw

Do not lubricate throttle levers or shoulder screws.

Final Powerhead Assembly

Install the reed plate and throttle body assemblies. Refer to Intake Manifold Service on p. 165.

Install oil recirculating hoses and check valves.
Refer to OIL RECIRCULATION DIAGRAM on p. 172, or POWERHEAD VIEWS on p. 216.

Install thermostat and pressure valve assembly.
Refer to THERMOSTAT AND PRESSURE RELIEF VALVE SERVICING on p. 190.

Install electrical harness.

Install fuel injectors and ignition coils. Refer to Fuel Injector Vapor Separator and Fuel Injector Service on p. 160.

All injectors must be installed in their original location. Improper injector installation can result in powerhead failure.

Install stator and flywheel. Refer to FLYWHEEL AND STATOR SERVICING on p. 133.

Install fuel pump assemblies, fuel manifolds, and filter. Refer to FUEL COMPONENT SERVICING on p. 158.

Install the oil tank and oil injection hoses. Refer to Oil Tank Assembly on p. 181.

Install the electric starter. Refer to Starter Installation on p. 140.

Install EMM. Refer to EMM SERVICING on p. 96.

Install spark plugs. Refer to Spark Plug Indexing on p. 69.

To prevent fire and explosion hazard, make sure all electrical and ignition wiring is routed and clamped in original positions.

Powerhead Mounting

Coat the driveshaft splines with Moly Lube. Do not apply lubricant to end of driveshaft.plines.

Be sure water tube is placed in upper and lower grommets.

1. Water tube
2. Grommet

Slowly lower powerhead onto exhaust housing. If necessary, rotate flywheel in a clockwise direction to align crankshaft and driveshaft splines.

Apply Triple-Guard grease to the threads of the powerhead screws.