Start….

Small Gas Engine Measurements Tips for a Smooth Rebuilding Process

Outline Introduction to tools How to use tools What areas to measure How to measure

Tool Types Telescoping Gauge Gap Gauge Micrometer Feeler Gauge Caliper Gauge Ruler

Micrometers Reading a micrometer Use two 90 degree measurements for round surfaces Is used with other tools Areas to use for small gas engines Journal measurements for crankshaft Cylinder measurements Piston measurements

Feeler and Gap Gauges Gap gauges are used to measure spark plug gap Feeler gauges are used in making extremely thin measurements Use a feeler gauge Ring measurements Ignition point gap Valve tappet clearance

Measurements to Check Compression check Spark plug gap Ignition point gap Armature air gap Crankshaft Cylinder Piston and rings More...

Valve and tappet clearance Carburetor float height

Compression Check Two main ways to check compression Using a compression gauge Rotating the flywheel in the wrong direction

Spark Plug Gap Check condition of spark plug first Use a Gap Gauge Check engine manual for specs Gap

Ignition Point Gap Use a feeler gauge to check Check manual for specs Adjust size of gap as needed Make sure points hit squarely Adjustment screw

Armature Air Gap Use a thick piece of paper or normal cardboard to measure To adjust loosen screws on sides and slide up or down as needed Adjustment Air Gap Screws Flywheel

Crankshaft Use micrometer to measure Compare results to manual specs Get journal measurements for Drive end Connecting rod Magneto end

Crankshaft Connecting Rod Journal Drive End Journal Magneto End Journal

Cylinder Use a telescoping gauge or an inside caliper gauge with a micrometer See engine manual for specs Check more than one depth Top, center, and bottom of travel Most wear will occur at the top due to ring travel Make sure to check each depth twice at 90 degrees to the first

Piston and Rings For the piston use a micrometer Take measurements at top, bottom, and skirt of piston Compare results to manual specs More...

Use a feeler gauge for all ring measurements …Rings Use a feeler gauge for all ring measurements Check ring side clearance with rings in piston ring grooves Remove rings for end gap measurements Use piston to evenly place rings inside cylinder for measurements More...

….Rings Remove and replace rings carefully with a ring expander Compare results to manual specs

Valve and Tappet Clearance Make measurements with a feeler gauge Check results against engine manual specs Make measurements while the valves are closed

Carburetor Float Height Measure float height with a ruler Check manual for suggested height Adjust height to acquire the correct fuel intake

Summary Introduction to tools How to use tools What areas to measure How to measure

The End