Just did oil change following break in. The manual says 100 hr. Or first year.
Figured it couldn't hurt so since it it way earlier than required ,kept it easy by not doing filter. Manual says 2 quarts. I pulled out 2and 1/2.
I think there are some misconceptions about "towing", the shut off valve or clamping would only be done/used if you were being towed while on the water if you were to ever run out of gas or break down and need a tow.