Rubicon Starting issues

I have a 2015 Honda Rubicon 4X4, IRS,PS,Diff Lock, all the bells and whistles.
Since I’ve bought it, its always had issues starting. While it was under warranty the dealer said, it was set up wrong and didn’t have oil on filter. Dealer put oil on filter and problem, never really went away. Now its off warranty and dealer said, it could be vaulves… I checked and they did appear off a little and I fixed that. Its still starts real hard. I mean it will turn over for about 5-15 seconds till if fires up. Almost like its, not getting fuel.
Anyone know of any issues or got advice on possible repairs I could make. Don’t trust dealers, so I do all repairs at home.