KELVIN LOW TENSION IGNITION
"KELVIN" Engines sold prior to number 2,000 were fitted with "low tension" ignition. This type of ignition is perfectly satisfactory if maintained in proper repair and adjustment, but if allowed to wear unduly "misfiring" results. The parts are inexpensive and should be renewed whenever they become slack.
FIRST ADJUSTMENT.--Retard the ignition (flat bar forward), turn the engine slowly until No.1 ignition rod drops, slacken the nuts above the buffer spring, bring the lower one gradually down until it touches the spring. From this position give it one complete turn further down. This will raise the ignition rod and prevent it falling hard on the cam as shown at "A."
SECOND ADJUSTMENT.--Adjust the coned nut exactly to the level shown at "B."
THIRD ADJUSTMENT.--Detach the spring from the grooved nut, slacken the nut with the spanner provided until the wiper can be slewed round on the vertical spindle. Adjust the position of the wiper so that it has a travel of about one-eighth of an inch, when the ignition rod is raised and lowered by hand. The wiper must be slightly clear of the ignition rod when up.
TO REMOVE THE IGNITION ROD.--Hold the lower buffer nut with one spanner while screwing off the thin rod with another spanner.
TO SET THE MAGNETO.--Should the chain be removed and not replaced in the same teeth, the chain boss on the magneto will require to be re-set. Prise off the chain boss. Advance the spark bar to half travel. Open compression cocks. Turn engine slowly till the forward ignition rod drops. In this position, with the chain and boss replaced loosely on the spindle, turn the magneto spindle till the saw cut in the end is up and down. Screw up the nut of the chain boss moderately tight.
CAUTION.--Do not turn the engine with the chain hanging down from the cam shaft.
THE STARTING DEVICE.--This is put in action by slackening the wing nut, and should be put out of action as soon as the engine starts by tightening the nut. The device consists of an arrangement for accelerating the magneto at the moment the ignition rod drops. The effect of this is to produce a robust spark, even although the engine is only being slowly turned. The action is as follows:--Just before the ignition rod drops the cam shaft is arrested and in this position it remains while the engine revolves beyond the point of ignition. The cam shaft is suddenly released and by the action of springs, flies rapidly past the ignition point. The cam shaft must not "fly" before the ignition rod has dropped.