If you've spent some churning it over on the starter, smell the exhaust. If it doesn't smell of petrol, then the fuel system is suspect. To check for sparks, pull a plug and rest it on something earthed (head, bulkheead), and look for a spark when you crank it. A fuel-air mixture should come out of the plug hole at the same time.
SEP field working, not spotted in 103,100 miles. Some photos on webshots, updated 25 Jan