Maintenance - Ransomes MINOR MK. 7 Instructions For The Operation And Maintenance

10 RANSOMES SIMS & JEFFERIES (AUSTRALIA) PTY. LTD.

MAINTENANCE.

ENGINE.
If trouble is experienced when star ng the engine through the sparking plug becoming wet
and oily, the crank case should be drained by taking out the small plug which will be found
at the base on the le -hand side of the crankcase. This trouble occurs through over-flooding
of the carbure or or by leaving the petrol turned on when the machine is not in use,
allowing the oil to se le in the carbure or.
DECARBONISING.
Decarbonising the Villiers Two-Stroke Engine is quite straight forward, because of the
simplicity of this type of unit. The following points, however, are worth special a en on.
When removing and replacing the cylinder, care should be taken not to twist it round the
piston — it should be pulled off or pushed on straight so that the rings cannot catch in any
of the ports and break.
All carbon should be removed from inside the piston head, as well as from the top of the
piston and the cylinder head.
The ports in the cylinder, par cularly the exhaust port, should receive careful and should be
kept clean, but on no account must the size or shape of these ports be altered by filing.
Piston ring grooves must be kept free from carbon in order to leave the rings quite free.
Piston rings should be bright round their surface which makes contact with the cylinder
bore. Should wear cause the joint gap to exceed in. when in the cylinder, the piston ring
should be replaced.
Carbon will form on the gudgeon pin at either side of the small end bush, and should be
carefully removed, otherwise difficulty will be experienced in removing the pin from the
piston. The small end bush and the piston bosses should be kept quite free from carbon.
It is of the utmost importance that silencers and exhaust pipes are kept quite clean
internally, and that a heavy deposit of carbon is not allowed to accumulate. This would
cause back pressure and of power.
It is important that air leaks should be avoided. The connec on between carbure or and
induc on pipe must be absolutely air ght and a er dismantling the engine, new washers
should be fi ed at the induc on pipe joint and cylinder base joint if the original ones have
been disturbed.
The engine should be decarbonised at the end of each season.
VILLIERS JUNIOR CARBURETTOR.
This is of the concentric float chamber type, allowing the machine to be worked on
undula ng grounds without affec ng the running of the engine.
In this carbure or, a taper needle is a ached to the thro le and provides a correctly
adjusted mixture at all thro le openings.