“SUN” SERVICE STATION

Sun (Auckland), Volume II, Issue 592, 19 February 1929, Page 6

“SUN” SERVICE STATION

rTiHEi “Motordom" section of The Su r includes In its service to readers a A Queries and Answers Department, the object of which is to give accurate information regarding mechanical and touring subjects. Whatever the particular puzzle may be in either diagnosing Irritating troubles, or motoring information of any kind, “Headlight” will endeavour to help, or refer the point to men who are recognised automobile experts in their respective lines. All communications must be accompanied by the Inquirer's name and address (not for publication), and sent to THE SUN “Service Station, Motordom,” THE SUN, Auckland, Answers will appear weekly in this column.

J.C., Otahuhu, writes inquiring about the new compulsory insurance scheme. This will be dealt with in a special article next week. A. —Would you tell me the correct inflation for balloon tyres of a Studebaker Standard 6 Victoria? Why is the pressure different for front and rear? If travelling in second, what may be the maximum speed? * * * (1) and (2); Front and rear should be lIS pounds. (3): 25 miles an hour or less. B. —My light six has recently developed the bad habit of intermittent missing on rare occasions, although the magneto and the switch appear to be in good order. * * ♦ Your trouble is almost certainly caused by a short circuit between the magneto and the switch. Probably the wire is held by clips to the frame, and you cannot see it; but I am sure that if you take it off you will find that, somewhere, the insulation has rubbed off and the bare wire is making contact with the chassis. This, of course, acts as an intermediate switch, and cuts out the spark whenever wire and chassis touch. Your best plan would be to purchase and fit an entirely new switch wire, and then your troubles should be cured. “Webb.”— My Buick has developed ; a mild chattering noise about the : valve gear, which I think must be the

cams wearing-. Do you think I ought to have new cams fitted? Those now fitted are quite new. My opinion is that this trouble is due to the valve cages being loose on the head. I have experienced a similar noise due to this cause, and would suggest that you take special precautions to see that the cages are tight, as sometimes they get carboned around the side and do not go down properly on their seats. The cam wear, I think, can be written oft' as an unlikely cause, as I have never seen a Buick camshaft worn sufficiently to create any serious noise. T.W.H.—Do you think it probable that a carburettor would “sweat’* in this warm weather, as I have sometimes found a little pool of benzine under my car. * • * * The reason for the pool of petrol under the car is merely flooding of the carburettor. If metal sweated, as you suggest, it would happen all the time. As you only find the petrol occasionally, obviously the trouble is not due to a punctured float, but merely to the valve not seating. This might be caused by two things—tin* valve shoulder is worn and needs to be ground into the seat, or a tiny bit of dirt gets into the space and holds the needle out of its seat. The last sounds the more likely. 1 would [ suggest that you thoroughly clean l the carburettor occasionally.