UNEVEN IDLING

NZ Truth, Issue 1212, 21 February 1929, Page 19

UNEVEN IDLING

Fussing with the carburettor when the engine will not idle smoothly may be courting an assortment of additional troubles. THERE are other things besides incorrect mixture that can cause uneven idling 1 . One of the most important of these is a leaky valve guide. Where valve stems or. -.their guides, are. worn air is sucked into the cylinders through these channels. Because only a little air. can leak through m this fashion the driver cannot detect any difference m the running of his engine when going at normal speeds, but m idling the air leaks serve to lean out the gas mixturn to a point where firing- is irregular.

Bpcau.se only one of two valve guides are leaking air only one or two cylinders are receiving the extra lean mixture. Just as m the case of uneven compression, this causes uneven .idling 1 . ■ " ■ Fouling- of spark plugs is not always an indication of oil trouble. This condition may be caused either from too much oil m the crank case, or worn rings. The ignition coil and condenser should, be tested, as the spark may- be too weak to assure a hot enough spark to ignite and burn the g-ases and oil accumulated.