Home Random Page


CATEGORIES:

BiologyChemistryConstructionCultureEcologyEconomyElectronicsFinanceGeographyHistoryInformaticsLawMathematicsMechanicsMedicineOtherPedagogyPhilosophyPhysicsPolicyPsychologySociologySportTourism






All spark plugs must be earthed (grounded) against the cylinder head

is a risk of atomised fuel escaping from the plug holes and igniting. As a safety precaution, cover the valve cover with rag. Turn the ignition switch ON and kill switch ON, open the throttle fully and crank the engine over on the starter motor for a couple of revolutions until the gauge reading stabilises.

6 After one or two revolutions the pressure should build up to a maximum figure and then stabilise. Take a note of this reading and on multi-cylinder engines repeat the test on the remaining cylinders.

7 The correct pressures are given In Chapter 1. If the results fall within the specified range and on multi-cylinder engines all are relatively equal, the engine is in good condition. If there is a marked difference between the readings, or if the readings are lower than specified,


inspection of the top-end components will be required.

8 Low compression pressure may be due to worn cylinder bores, pistons or rings, failure of the cylinder head gasket, worn valve seals, or poor valve seating.

9 To distinguish between cylinder/piston wear and valve leakage, pour a small quantity of oil into the bore to temporarily seal the piston rings, then repeat the compression tests (see illustration 3).If the readings show

Bores can be temporarily sealed with a squirt of motor oil

a noticeable increase in pressure this confirms that the cylinder bore, piston, or rings are worn. If, however, no change is indicated, the cylinder head gasket or valves should be examined.

10 High compression pressure indicates excessive carbon build-up in the combustion chamber and on the piston crown. If this is the case the cylinder head should be removed and the deposits removed. Note that excessive carbon build-up Is less likely with the used on modern fuels.

Checking battery open-circuit voltage

A

Warning: The gases produced by the battery are explosive - never smoke orcreate anysparks in the vicinity of the battery. Never allow the electrolyte to contact yourskin orclothing - if it does, wash it off andseek immediate medical attention.


REF»46 Fault Finding Equipment



 



Date: 2016-01-14; view: 637


<== previous page | next page ==>
Abnormal frame and suspension noise | Continuity check of rear brake light switch using a continuity tester
doclecture.net - lectures - 2014-2024 year. Copyright infringement or personal data (0.006 sec.)