You don't say what kind of ignition system your machine has but if it he old kettering type (with coil. points and condensor) it could need the points cleaning and gapping (or replacing) or the coil could be breaking down or the condensor could be onthe fritz. To test the coil tke the plug from the cylinder head and put the spark plug into the plug cap and hold the plug against he cylinder head and turn over the engine (get help if needed) and see if the spark jumps the gap . If it doesn't take plug cap off the lead and hold lead close to head or clean metal and repeat the turn over. If spark now jumps the gap the problem is inthe plug cap or plug. which should should be replaced. (by the way just because you put in a new plug doesn't mean that the plug ok as new ones can be faulty)These tests apply which ever system you have. If you still have no or an intermittent spark try a new lenth of plug lead . believe it or not they can corrode internally especially if sroredin a damp shed etc. If still no spark from the lead coilis duff Try borrow another one to compare before buyind new one. If your machine doesnt hve a coil it may have an ignition module which is charged from magnetic rotor on crankshaft.It is possible tha the module( a litle box with ignition lead emerging from it in close proximity to the magnets on the magneto i've mentioned ) this is not repairable wihout special tools aqnd knowledge. Only replacement is possible by average D.I.Yer. If none of this helps you will have to Get help from a profassional. By the way are you sire the problem is the ignition side . Is your fuel fresh it does deterorate if left in the machine, Check your carburettor isn't full of water (even water in fuel) or has blocked jets etc. sorry I can't be there to have a look but I hope this helps a bit
John Mantova, March 2012
