Hi,
I have a 2021 EFI and might be able to help... .

When you do a cold start and the engine is running, do you have a fast idle? Is there any popping or sputtering or black smoke upon cold start up. Look inside your airbox before a cold start. Is there any condensation or moisture inside it? Try a cold start with the air box open and without the air filter, and let me know what happens.

 

Check valve clearance. To tight it’s very hard to start cuz there open.

 

Good point. That could happen if the exhausts are tight. I had that happen on my KLX650.