Is it a new engine / plug? Refer to the manual and set the high and low speed needle valves to factory specs. Roughly the low end should be flush and the high should be 2 turns out (at least that is what it is for my OS .15 CVRX). Take the plug out and screw it into your 4way wrench. Put your CHARGED glow starter to it and see if it glows bright orange/white. If so, screw it back in. If not, put a new plug in it (I use OS #5). Prime the engine, apply heat to the plug and give it a crank. If it doesn't crank, find someone who really knows engines b/c I'm not that guy.
Good luck!