Problem: Engine Won’t Start

• Airflow is restricted
• Fuel doesn’t reach the carburetor
• Engine and/or fuel system has an air leak
• Fuel mixture needles not properly set
• Glow plug fails to function

Solution

• Clean air filter
• Clean fuel filter
• Inspect fuel tank, line and engine for poor seals
• Return needles to factory-recommended settings
• Replace glow plug and/or change glow plug filter

Problem: Engine Starts, then dies

• Idle is set too low
• Low-speed needle is set to rich
• Low-speed needle is set to lean
• Clutch is binding
• Glow plug is loose
• Glow plug is fouled
• Piston and sleeve are worn
• Damaged bearings in the clutch bell

Solution

• Adjust idle-speed screw clockwise
• Lean out low-speed mixture
• Richen low-speed needle
• Take clutch apart and fix the problem
• Tighten glow plug
• Replace glow plug
• Seal engine with high temp sealer
• Clean or replace bearings

Problem: Engine bogs when given full throttle

• Low-speed needle is set to rich
• Clutch engages too quickly
• Glow plug is too cold

Solution

• Lean out low-speed mixture
• Replace clutch spring/shoes
• Install a hotter plug

Problem: Engine doesn’t idle correctly

• Engine might have air leak
• Low-speed needle is set to lean

Solution

• Seal engine with silicone
• Richen low-speed needle

Problem: Engine bogs or dies at high speed

• High-speed needle is set to lean
• Fuel flow is restricted
• Piston and sleeve are worn

Solution

• Richen high-speed mixture
• Clean fuel filter
• Replace piston and sleeve