Specifications
HONDA GN4 4-stroke oil or equivalent motor oil API service classification SF or SG Viscosity SAE 10W-40
Evap Cav Solenoid Valve
Connect a pressure pump to the No. 6 tube fitting that goes to carburetor. Damage to the EVAP CAV solenoid valve may result from use of high pressure air source. Use a hand oprated air pump only. With the ignition switch OFF, pump air through the No. 6 tube fitting. Make sure the air flow out from No. 4 fitting, and does not flow out from No. 7 fitting. Turn the ignition switch ON, pump air through the No. 6 tube fitting. Make sure the air flow out from No. 7 fitting, and does not flow out from...
Pilot Screws
2. Warm the engine up to operating temperature. 3. Stop the engine and connect a tachometer according to the tachometer manufacturer's instructions. 4. Start the engine and adjust the idle speed with the throttle stop screw to the specification shown below. 5.Turn the No. 3 pilot screw in or out slowly to obtain the highest engine speed. 6. Perform step 5 for all the carburetor pilot screws. 7. Lightly open the throttle 2 3 times, adjust the idle speed to the specification above with the...
Radiator Coolant
Check the coolant level of the reserve tank with the engine running at normal operating temperature. The level should be between the UPPER and LOWER level lines. If necessary, add recommended coolant. Remove the seat page 2-2 . Remove the reserve tank filler cap and fill to the UPPER level line with 50 50 mixture of distilled water and antifreeze. Reinstall the filler cap.
Right Upper Cowl Cover Right Inner Panel
Align the inner panel with the frame boss and lower edge of the fuel tank, then install the boss into the fuel tank gromment. Install the both upper cowl cover. NOTE Align the upper cowl covers with the meter panel bosses. Temporarily install the special bolts. Install the upper ends of the windscreen special bolts cap nuts. Tighten the cap nuts while holding the special bolts. Tighten the special bolts.
Oil Level Inspection
Start the engine and let it idle for 2 3 minutes. Turn off the engine and support the motorcycle on its center stand. Remove the oil level dipstick wipe it clean. Reinstall the oil level dipstick, but do not screw it. Remove the oil level dipstick and check the oil level. If the level is below the lower mark on the dipstick, fill the crankcase with recommended oil. Fill the recommended engine oil up to the upper level mark. HONDA GN4 4-stroke oil or equivalent motor oil API service...
Breather Tube
Route the fuel level reserve sensor unit wire. Remove the fuel tank support and lower the fuel tank. Be careful not to damage the inner panel bosses. Connect the fuel level reserve sensor 3P Black connector. Install and tighten the fuel tank mounting bolts. nner panel bosses into the fuel tank i
Lower Bracket
Remove the crankshaft hole cap and O-ring. Turn the crankshaft clockwise, align the T mark on the ignition pulse generator rotor with the index mark on the ignition pulse generator rotor cover. The timing marks IN and EX on the cam sprockets must be flush with the cylinder head surface and facing outward as shown. If the timing marks on the cam sprocket facing inward, turn the crankshaft clockwise one full turn 360 and realign the timing marks with the cylinder head surface so they are facing...
Idle Drop Procedure
If the engine must be running to do some work, make sure the area is well ventilated. Never run the engine in an enclosed area. The exhaust contains poisonous carbon monoxide gas that may cause loss of consciousness and may lead to death. Run the engine in an open area or with an exhaust evacuation system in enclosed area. Make sure the carburetor synchronization is within specification before pilot screw adjustment page 3-16 . The pilot screws are factory pre-set. Adjustment is not necessary...
Brake Fluid
Do not mix different types of fluid, as they are not compatible with each other. Do not allow foreign material to enter the system when filling the reservoir. Avoid spilling fluid on painted, plastic or rubber parts. Place a rag over these parts whenever the system is serviced. When the fulid level is low, check the brake pads for wear see next page . A low fluid level may be due to wear of the brake pads. If the brake pads are worn, the caliper piston is pushed out, and this accounts for a...
Float And Jets
Handle all jets with care. They can easily be scored or scratched. Install the pilot screw and return it to its original position as noted during removal. Perform the pilot screw adjustment procedure if a new pilot screw is installed page 5-21 . Install the float and float valve in the carburetor body, then install the float pin through the body and float.
Oil Pressure Inspection
If the oil pressure indicator light remains on a few seconds, check the indicator system before checking the oil pressure. Warm up the engine to normal operating temperature approximately 176 F 80 C . Stop the engine and disconnect the oil pressure switch wire connector from the switch. Remove the oil pressure switch and connect an oil pressure gauge and attachment to the switch hole. Oil pressure gauge 07506 3000000 Equivalent commercially available in U.S.A. Oil pressure gauge attachment...
Remarks
Liquid sealant Three Bond 1207B, Hondabond 4 or equivalent Ignition pulse generator cover bolt threads marked A Do not apply to the thread head. 3 4 mm 0.1-0.2 in
Evaporative Emission Control System California Type Only
This model complies with California Air Resources Board evaporative emission requirements. Fuel vapor from the fuel tank and carburetors is routed into the evaporative emission EVAP canister where it is absorbed and stored while the engine is stopped. When the engine is running and the evaporative emission EVAP purge control valve is open, fuel vapor in the EVAP canister is drawn into the engine through the carburetor. At the same time, the EVAP carburetor air vent CAV solenoid valve is open...
Clutch Fluid
Do not mix different types of fluid, as they are not compatible with each other. Do not allow foreign material to enter the system when filling the reservoir. Avoid spilling fluid on painted, plastic or rubber parts. Place a rag over these parts whenever the system is serviced. When the fluid level is low, check entire system for leaks. Turn the handlebar to the right so that the reservoir is level and check the clutch fluid reservoir level through the sight glass. rHQRI2 . ft E fl BE AM DjjOS...
Carburetor Synchronization
Synchronize the carburetors with the engine at normal operating temperature, transmission is in neutral and the motorcycle supported securely on a level surface. Remove the following Fuel tank page 2-2 Lower cowl page 2-7 Remove the vacuum plugs from the engine intake ports. Screw the adaptors in the intake ports. Install the 3-way joint to the fuel valve vacuum tube. Connect the fuel tube and vacuum tube to the fuel Connect the vacuum gauge tubes to the adaptors and 3-way joint.
Oil Cooler
Apply clean engine oil to the new O-rings, and install them onto the oil cooler pipes. Install the oil cooler pipes into the lower crankcase. Install the oil cooler to the upper cowl stay. Install the collars and tighten the mounting bolt
Trim Clips
Remove the windscreen upper end special bolts cap nuts. Remove the special bolts and upper cowl covers. Remove the lower cowl page 2-7 . Remove the inner panel trim clips. Release the inner panel from the frame boss. Release the inner panel boss from the fuel tank.
Master Link
Remove the excess drive chain links from the new drive chain with the drive chain tool set. Include the master link when you count the drive chain links. STANDARD LINKS 110 links REPLACEMENT CHAIN DID DID50ZVS-120ZB RK RK50LFOZ1-12QLJ-FZ Never reuse the oil drive chain, master link, master link plate and O-rings. Assemble the new master link, O-rings and plate. caution Insert the master link from the inside of the drive chain, and install the plate with the identification mark facing the...
Trim Clips 1
Install the headlight unit page 19-5 . Install the air guide and secure it with two trim clips. Install the cushion rubbers onto the rearview mirror bracket. Place the upper cowl onto the cowl stay and connect the headlight sockets. Install the upper cowl aligning the bosses on the headlight unit with the rubber grommets on the upper cowl stay. Align the rearview mirror holes on the upper cowl with the bosses on the upper cowl stay. Install the two trim clips that connect to air guide.