Mariner 15 won't start

[Tim M]

My mariner 15hp 2 stroke won't start. Up until now it's never had a single problem. It started first pull after not being used for 6 months at the beginning of the year, and generally starts first pull now. It was unfortunately run on "moped" 2 stroke every day for two weeks, when it apparently ran fine. It then had a week's break. I put it in the water this morning, but I could not get it to start. I've looked over the wiring to the stop and kill switches - all seems fine. I've taken the plugs out, given them a clean and put them back in. Still not a sausage. I'm concerned the problem is to do with the lack of decent oil running through it.
Any advice please?
PS. Is now running on proper TCW3.

[Nos4r2]

Have you got a spark at the plug?