Vire 7 - Troubleshooting

The information on this page comes mainly from the original Operator's Manual, and is intended as an aid in diagnosing problems. If you've got a problem that your trying to diagnose and/or fix, it may also be worth your while to visit the Hints and Tips pages.

Start by checking the basics - make sure that the Stop/Run Switch (if fitted) is switched to Run and make sure that there is fuel in the tank and that it is reaching the engine. After that, most cases of failure to start are due to problems with the spark plug, so check the spark plug before you do anything else. If that doesn't work, determine which of the following descriptions most closely matches the problem, then check against the "X"s in the table below for a list of possible causes.

Problems are tabulated under five headings:

  1. Engine does not start or it stops during running
  2. Engine runs irregularly
  3. Engine output is too low
  4. Engine "knocking"
  5. Flywheel striking back
1 2 3 4 5 Possible cause
X O O O O Fuel tank empty
X O O O O Too much choke
X O O O O Water in fuel (often characterised by a loud 'spit' back through the carburettor (a "psst" sound), following which the engine stalls)
X X O O O Carburettor main nozzle clogged
X X O O O Carburettor strainer clogged
X X O O O Fuel tank vent hole blocked
X X X O O Unsuitable fuel
X X O O O Air leak in carburettor
X X X O O Spark plug electrodes dirty or burned
X X O O O Spark plug gap too big
X X O O O Water drops on spark plug electrodes
X X O O O Defective insulation
X X O O O No contact between plug terminal and cable
X X O O O Magneto contact breaker gap short-circuited or insulation dirty
X X O O O Magneto contact breaker gap too big or too small
X X O O O Ignition cable (magneto end) or inner wires loose
X X O O O Magneto wet
X X O O O Other reasons
X O X O O Piston rings stuck
O O X O O Ignition advance too small
O O O X O Carbon on pistons or at cylinder end
O O O X X Ignition advance too great

If the above doesn't solve your problem, it may be worth visiting the Vire pages at Fairways Marine.

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