Thanks for your advice, I have taken off the fly wheel and the points and coil are ok, no problems there. To give you more information on the Scott Bonnar my Father bought it from Clyde Industrial Park on 25th January 1968 the engine number is 201-19137 and the model number is 48 � 04038. My Father in his collection had the original sales brochure and owners manual and even the newspaper advertisement. In the paper work there are two pages on the servicing the wipec Magister unit which is the round type. The photos in the sales brochure show the round Wipec Magister unit however on my mower at some point this was a problem and was changed and now it has a cylinder type unit. Please see attached photos.