I live in michigan and have already had my boat in the water this year to text it after replacing gimbal ring. Now a few nights this week they are calling for like 29deg. over night. I have a 94 scarab with twin 350 and alpha one drives. Do you think it will be ok to leave it outside with these temps? i wouldnt think it would freeze enought to hurt anyting but im not sure??

Drain the blocks and exhaust and you will have nothing to worry about..

They're not going to freeze overnight in those temps.

If it's insured, put a 100W lamp in the engine bay. It's not likely to freeze hard enough to break anything but you'll sleep better. I also keep a cup of water next to my boat in the garage for a little more insight as to what's going on.

old style lead light left on in the bilge if you are that worried, but I agree 29 degrees for a few hours one night is not going to split metal

Its warm enough in the day that tho motors shouldnt freeze overnight. I put a block heater on mine which will not only keep the block warm but the radiant heat in the engine compartment will make it all good. Im not too worried without it but I have it, so to be certain Ill just use it. If it looks like its going to be retarted cold ill just drain everything out.

If it only gets to 29* for the overnight low, you have nothing to worry about.
Rule of thumb is 24* for 24 hours.

Ok thanks guys I kinda thought the same thing about the temps but wanted reassured. Im still a worrier bc this boat is our baby so I did go out and drain the block and manifolds bc I probably wont b using it for little while anyways and the 20 min it took was worth the piece of mind

Exactly what I'd have done, 20 min for peace of mind is a small price !