Synthetic vs. petroleum based 2 stroke oil?
Recently purchased a new (to me) boat and the previous owner has been running full synthetic in it. I am reluctant to change horses mid-stream, but is there any real advantage for using synthetic over petroleum based 2 stroke oil?

I had 200hp Mercury with auto oil removed here what I noticed going from semi synthetic to full synthetic way longer spark plug life the inside of around the prop went from dark gray to a lighter gray smoother idle. I was weekender part time fisherman. In my opinion if the previous owner cared enough to spend the money on full synthetic I would not change. I believe full synthetic does not carbon up as likely.

Used Amsoil for 19 hears in my lower unit and the gas mixture in my Yamaha 150. Been using it for the last 6 years in my 225hp Mercury, zero problems, I'll never switch.

Used Amsoil for 19 hears in my lower unit and the gas mixture in my Yamaha 150. Been using it for the last 6 years in my 225hp Mercury, zero problems, I'll never switch.

Amsoil is a good oil, also Belray make a good oil

Synthetic is cleaner burning, that was all I used when I ran a 2 stroke

Yes, dino oil carbons up way worse, stick with a premium plus synthetic

Premium Plus, which is a semi-synthetic. Only time NOT to use a semi, or full synthetic is during the break in of a new motor.

At 12 years I blew my head gaskets while stuck in hydrilla at Choke. Took off heads to replace heads, there was zero carbon build up, not a speck, looked like a new engine. Sticking with Amsoil. Got the head gaskets for $105 for both overnighted, which was 1/2 price, dealer wanted double that. Boats.net has fantastic prices.