Tohatsu 4hp 4stroke Idle surging

"Greetings,
I have a 2008 Toh

"Greetings,
I have a 2008 Tohatsu 4HP 4stroke that I bought brand new. It has the integral tank and that is the only tank I use. Haven't tried external yet.

The motor seems to run well high idle to top range. However I use this motor for trolling exclusively and the low idle is poor. At low idle, the motor surges up and down, I would estimate 200-300rpm. It is quite annoying and elusive to what may be causing it. I have tried the idle adjust screw to find a sweet spot but doesn't help. Checked the fuel cap vent, lines, and fuel. I haven't tried an external tank yet, will do that next. The idle surge is quite regular. It's disapponinting since this engine is brand new but will keep trying to solve the problem.

I checked the archive here and didn't see a similar problem so was hoping for any additional advice before I dig in. Thanks."

"Run it by a dealer...Either a

"Run it by a dealer...Either a tiny piece of casting didn't get clear of the carb before assembly(they can clear it) or you will need a new carb. It's always possible it could just be a bit of trash in it, but a regular surge implies an actual fault."

"Thanks. I may resort to that.

"Thanks. I may resort to that. I have no problem taking it apart myself but not sure if that screws my warranty or not.

The surging is low frequency. In other words, the motor runs for a minute or two fine, then surge, then back to normal and will repeat again. (Sorry, I changed my username)."

"It would really be better if

"It would really be better if you didn't take it apart yourself...At this point. It shouldn't screw your warranty, but if you lose a part or bend the float wrong when you put it back in that will just delay the dealer from finding the source of your problem later. You may even have a CD module tripping in or out. Any time you have have surge that is regular in terms of time or at a specific speed it goes from probable trash to probable defective part. Utilize that warranty you paid for when you bought the engine "