Re: Do I need to start my tohatsu9.8 weekly during winter time?
You didn't mention your location. Depends on how cold it gets where you are, and if you're storing your boat indoors or outdoors. If you're fishing every few weeks you don't need to do much except make sure there is no water in the motor to freeze.
Here's what I would do:
1. Make sure you have recently changed the lower unit gear oil. This way any water contamination has been removed and is not at risk to freeze and become a problem on the seals or lower unit itself.
2. Make sure there is no water in the motor passages from your last trip. Typically after fishing I pull the boat 1/2 way up the ramp and fire the motor(s) up for just a few seconds to blow out any trapped water.
3. Treat your fuel with Stabil or some other additive that helps keep fuel fresh. Also, try to keep your fuel tank(s) topped off to prevent condensation.
4. Keep any batteries fully charged, preferably indoors.
5. If your motor will sit for more than a month unused I would suggest pulling the plugs and giving each cylinder a shot of fogging oil or WD-40 to prevent rusting.
I think that should be about it - I'm sure someone else will chime in if I forgot to mention something.