152fmh Engine Service Manual Instant

Before turning a wrench, verify your engine code. The code is typically stamped into the lower left side of the crankcase, near the gear shifter. Decoding the 152FMH Engine Code 1 : Single cylinder 52 : 52.4mm cylinder bore F : Natural air cooling M : Motorcycle/powersports application H : 110cc displacement class Technical Specifications Specification Engine Type 4-Stroke, Single Cylinder, Air-Cooled, OHC Displacement 107cc (commonly marketed as 110cc) Bore x Stroke 52.4mm x 49.5mm Compression Ratio 9.0:1 to 9.7:1 Idle Speed 1500 RPM ± 100 RPM Spark Plug NGK C7HSA or Torch A7TC Spark Plug Gap 0.6mm – 0.7mm (0.024" – 0.028") Cooling System Forced Air Cooled Ignition Type CDI (Capacitor Discharge Ignition) 2. Fluid Capacities & Torque Specifications

Remove the four cylinder head cap nuts from the front face of the head, alongside the side retaining bolt.

Hold the adjustment screw in place and torque the locknut to 9 Nm. Recheck the clearance to ensure it didn't shift during tightening. Carburetor Tuning and Cleaning

Insert a 0.05mm feeler gauge between the valve stem and the rocker arm adjuster screw. 152fmh engine service manual

Disconnect the Black/White wire from the CDI plug. If the engine gets spark now, your kill switch, key switch, or wiring harness is shorting to ground.

Adjust while the engine is warm until the engine idles smoothly at roughly 1500 RPM without stalling or engaging the automatic clutch. 5. Electrical System & Wiring Diagram

Locate the 17mm bolt on the bottom-left side of the engine casing. Note: Do not confuse the oil drain plug with the angled 14mm cam chain tensioner bolt. Before turning a wrench, verify your engine code

Check fuel lines for kinks; clean or replace the inline fuel filter. Air leak at intake manifold

Black/Red (Source Coil): Should read between 300–500 Ohms.

If the engine stutters, bogs down under acceleration, or only runs with the choke on, the pilot jet is likely clogged with fuel varnish. Fluid Capacities & Torque Specifications Remove the four

Check the primary resistance (from the input tab to ground, should be ~0.5 to 1.5 Ohms) and secondary resistance (from the input tab to the interior of the spark plug cap, should be ~6k to 10k Ohms). 6. Comprehensive Troubleshooting Guide Probable Cause Corrective Action Engine Will Not Start (No Spark) Faulty kill switch / shorted wiring Disconnect the Black/White wire at CDI to isolate. Fouled or improperly gapped spark plug Clean, gap, or replace the spark plug. Failed CDI module or Ignition Coil Test resistance values; replace component if out of spec. Engine Will Not Start (Has Spark) Clogged pilot jet in carburetor Disassemble carburetor and clean out all jets. Stale or contaminated fuel Drain fuel tank and float bowl; refill with fresh gasoline. Low engine compression

Check valve clearance; inspect piston rings and cylinder walls. Incorrect air/fuel mixture