Briggs & Stratton 700 DOV Series, Repair Manual

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SYSTEMS CHECK
Most complaints concerning engine operation
can be classified as one or a combination of the
following:
• Will not start
• Hard starting
• Lack of power
• Runs rough
• Vibration
• Overheating
• High oil consumption
What appears to be a problem with the engine
may actually be the fault of the equipment.
Following is a list of some common engine
symptoms and their relationship to equipment
problems.
No Start - Hard Start
• Loose belt or blade
• Cranking under load
• Misadjusted controls
• Interlock system malfunction
Engine Will Not Stop
• Equipment stop switch not functioning
• Engine ground wire damaged or
disconnected
Vibration
• Bent cutter blades
• Loose spindles and couplings
• Bent/broken deck or weldments
• Bent crankshaft
• Loose equipment mounting bolts
• Damaged or worn belts and pulleys
• Out of balance impeller
Power Loss
• Bind or drag in moving parts of
equipment
• Grass build-up under deck
• No lubrication in equipment gear box
• Excessive belt tension
Once equipment sources are ruled out, the
cause for most of these symptoms can be
determined by performing a systems check in the
following order:
1. Ignition
2. Carburetion
3. Compression
This check-up can usually be done in a matter of
minutes and is the quickest and surest method of
determining the cause of such problems.
1) Check Ignition
Engine Stopped
With spark plug installed, attach Ignition Tester
#19368 to spark plug lead and ground the other
end of the tester (Figure 2-1). Pull the starter
rope or activate the electric starter (if equipped).
If spark jumps the tester gap, you may assume
the ignition system is functioning satisfactorily.
Figure 2 - 1
Engine Running
If engine runs but misses during operation, a
quick check to determine whether the ignition is
at fault can be made by installing Ignition Tester
#19368 between the spark plug lead and spark
plug (Figure 2-2). If spark is good but engine
misses, install a new spark plug.