I have a 2018 Z500 trail and all of a sudden it wll not start. all it does it turns over but will not fire. air filter clean, mass air senor clean, fuel injector has fuel coming out, fuel pump starts then stop like it should fuses good, battery good. the EFI light just flashes continuously as soon as the key is on. if there is a code i cant make out a code, was running fine one weekend then the next weekend was a no go. just checking for ideas before it goes to the shop. other then that no problems

[2015 Z Force 800 53/Trail EPS]

See if it has spark and compression. If so check the compression. If it has air,fuel,compression and spark at the right time, it has to run. Something is missing...just got to find out what.

yes it has spark new plug and compression within specs. wont even start with starting fluid all senors seem to be workinmg properly

Given what you've provided, and using starter fluid, my bet is that the spark plugs aren't being fired, and I would take steps to test that system.

The EFI flashing tells us it's unhappy about one or more circuits. First step is to dump any available codes. This is done with a reader (dealership will have these) or installing a jumper on the K-line. (There are posts in this forum for that).

Checking electrical connections is also prudent.

I have a 2018 Z500 trail and all of a sudden it wll not start. all it does it turns over but will not fire. air filter clean, mass air senor clean, fuel injector has fuel coming out, fuel pump starts then stop like it should fuses good, battery good. the EFI light just flashes continuously as soon as the key is on. if there is a code i cant make out a code, was running fine one weekend then the next weekend was a no go. just checking for ideas before it goes to the shop. other then that no problems

Try fiddling with the killswitch button. On mine I started just using the key and not starting/stopping using the killswitch. 1 out of 2 times it wont start until I push it in and out a few times... Give that a try.. sounds simple but it worked for me after the dealer found no issue.

UPDATE:
just got it back from shop. the valves were at a negative and the exhaust valves was loose. they cleared the codes and gave it its first service.  runs good now  time to pack of the toys and go play

Did they tell you what codes were being reported? That could be helpful to someone in the future.

Not sure what "valves were at a negative" means either.

"Exhaust loose" sounds like they did a lash adjustment.

no on the codes   intake valves were negative clearance what ever that means so they sey all valves to specs.  i still say take/ build these buggies with out the calif. crap on them and they would run better

The lash adjustment is a good thing. But that's not why it would not start.

There is something they aren't telling you.

But no matter, as whatever it was, it's fixed. Drive it like you stole it :-)