Sometimes won't start after 1 or more days of not using. After many attempts to start, changing fuel filter usually works. Seems to run fine after it starts. Usually will start the same day after shut off. Fuel filter doesn't look dirty and will work if installed later.
Thought it might be a lift pump problem so I installed a new lift pump and in line pre-filter. It didn't help. Then I dropped the fuel tank and checked for dirt, etc. and sprayed carb cleaner on bottom inlet screen. Tank and screen didn't have any noticeable dirt or build up.
Reinstalled tank after blowing out supply line from lift pump to tank.
Still have starting problem. Any Suggestions? I have run out of ideas!

 

Welcome to the site.

Tony