Model 2120 Tractor TM-4252 (Dec-70) General Information 10 Engine and Tractor Tune-up 20-1 Group 20 ENGINE AND TRACTOR TUNE-UP GENERAL INFORMATION Before tuning up the engine, determine whether a doubt, the following preliminary tests will help to tune-up will restore operating efficiency. If there is determine if the engine can be tuned up. PRELIMINARY ENGINE TESTING Service Specifications Reference Checking air intake system by means of vacuum gauge 14 to 25 in. (355-635 mm) water head; engine running at fast idle speed res "Fundamentals of Service, Engine" manual under "Diagnosis and Testing" a Check radiator for air bubbles or oil film Measure blow-by at crankcase vent tube * 436 Imp.
gals. /h. 524 US.gals./h. 1982 liters/h. Check compression which should be at least (using special tool No. 19.58-90.578) 300 psi (21 kg/cm2) res "Fundamentals of Service, Engine" manual under "Diagnosis and Testing" a Measure engine horsepower at powershaft (using a dynamometer) Record measured perfor¬ mance and compare with performance measured after carrying out "Engine Tune-up" * Measure with a standard gas gauge , placing hose over end of crankcase vent tube. The engine must be tested at 2500 rpm, normal running temperature and should be run in (at least 100 hours). Measure over a period of 5 minutes and multiply measured value by 12 (for hourly rate). Compare with values quoted above.
There is no undue wear on piston rings and cylinder liners if the measured value is lower than that quoted above. Should a further test be desired, carry out a compression test. If the " blow-by " reading is more than that quoted above, the decline in performance is due to excessive wear and the engine should be overhauled. Printed in Germany