Engine Block heater for 71 Mercruiser 165 (GM 250 CID) ?

[59Thompson]

Any advantage to installing a block heater for those transitional times when you still want to be on the water in a dock kept boat but the nights can drop into the thirties? Has anyone done this and was it worthwhile in your opinion? Thanks in advance for your input.

 

[Scott Danforth]

no, its not worth it.

if the boat is still in the water, the bilge will be at lake temp, not air temp

not to mention the heating elements require antifreeze, not lake water. and they are not SAE J1171 compliant, so your adding a fuse to the bomb.

now, they do make compliant bilge heaters. however they are not worth it.

 

[59Thompson]

Thanks Scott makes sense. Lake temps still near 70. This is my first I/O so much to learn.

 

[Scott Danforth]

if you just got the boat, make sure you do all the maintenance the prior owner neglected before you go out.

that includes, pulling the drive to do a drive service (raw water pump, pressure test and new fluids)
inspect the u-joints, gimbal bearing and bellows - replace as required
verify the alignment

then on the motor, service the points, change the engine oil and filter, change the fuel system filter, change plugs, cap, wire, rotor.

then move on to the trailer, service the bearings, brakes and coupler.

 

[59Thompson]

Thanks Scott, did those earlier this year, have a slight trim hose leak I just posted about. Swapped to new to me lower, wider trailer that should be ready soon and will have local dealer winterize next week.