Vire 7 - Operation and Running

Preparation of a New or Stored Engine

After storage, before the engine is put into service, the conserving oil must be drained from the crankase. This is simplified by pouring a cupful of 2-stroke fuel into the crankcase and then swinging the engine several times to and fro. The mixture is then drained out through the draining screw hole at the bottom of the crankcase.

The preserving oil in the cylinder is removed in a similar manner, by pouring a spoonful of fuel through the spark plug hole, when the piston is in the halfway position. The engine should then be rotated rapidly by the starter cord, the mixture blowing out through the spark plug opening.

Fuel and Lubricants

Any regular grade of petrol (gasoline) may be used. It is not necessary to use high octane or super grade fuel. The petrol should always be mixed with suitable oil, in the ratio of 1 part of oil to 33 or 50 parts petrol, as appropriate (1 part to 20 for the first 10 running hours). When filling the tank with fuel, use a fine mesh or chamois leather filter.

The gearbox should be filled to the level between the end and the mark of the dip stick. Use gear oil SAE 140 for the initial 50 hours, thereafter use SAE 90 gear oil (Webmaster's Note: Some owners prefer always to use SAE 140). The capacity is 0.85 litres* (1.5 Imperial pints or 1.75 US pints).

*Webmaster's Note: The original Operator's Manual suggests 0.7 litres under this heading, but then suggests 1.5 Imperial pints (1.75 US pints - equivalent to 0.85 litres) elsewhere in the Manual. Some later versions of the Manual advise the necessity of compensating for the tilt of the engine when filling the gearbox. Personal experience suggests that too much is better than too little (See "Stuck Solid" for a cautionary tale - and the Webmaster has had a similar experience, in reverse).

The grease cup on the inboard sterntube bearing should be filled with good quality water pump (HMP) grease.


(See Maintenance)

  1. Check that adequate fuel is available in the fuel tank.
  2. Make sure that the gear lever is in the neutral position.
  3. Open the fuel cock (if fitted). If using a portable fuel tank, pump fuel with the hand pump until resistance is felt.
  4. Open the cooling water sea cock.
  5. If the engine is cold, close the choke (the choke lever on the carburettor should be in the upright position).
  6. Open the throttle about one third.
  7. If a Stop / Run switch is fitted, switch it to run.
  8. For engines with electric start, turn the starting key to crank the engine.
  9. For manual starting
  10. When the engine has started, turn the choke off slowly and use the throttle to regulate the speed accordingly.
  11. If a supply of water is led into the exhaust manifold through a regulator stop-cock, this should now be opened.
  12. Move the gear lever into the required driving direction. The speed of the boat is now adjusted by means of the throttle lever.

Starting a Warm Engine

Starting is generally the same as for a cold engine, except that the choke should be left in the run position. No choke is used, because the mixture will be too rich and the engine will not start.

If the engine has been 'flooded' or 'over-primed' the engine will not start. Proceed as follows: -

  1. Check that the choke is off, i.e. in the run position.
  2. Close the high-speed mixture screw (Webmaster's Note: If you note the number of turns by which you close the screw, it will make it easier to re-set the screw later).
  3. Open the throttle completely.
  4. Rotate the engine vigorously, several times if necessary, until it starts.
  5. As soon as the engine starts, re-set the needle valve to the best position and adjust the speed of the engine by means of the throttle.

A very hot engine may refuse to start, even if not 'flooded'. In this case: -

  1. Check that the choke is off, i.e. in the run position.
  2. Open the throttle completely.
  3. Turn the fuel off.
  4. Give the engine several vigorous false starts.
  5. When the engine starts, adjust the speed of the engine by means of the throttle, then turn the fuel on.

Remember: NO CHOKE when the engine is hot

Top of Page Vire 7 Home Page Operator's Manual - Contents Site Map