how is this saildrive insulated

[VicS]

that's what I thought, back to drawing board as I defiantly have the single wire system with the body of sensors forming the earth, looks like I will be looking for a way of retro fitting a insulating spacer between engine and saildrive. perhaps I have one between block and bell housing, will move battery earth to engine block instead of bell housing and test. as I said the alternator is already earthed via B- on to the back of block via a short original lead so this would suggest block has never been earthed via any type of solenoid. got paris rhone alternator off at moment and looks very old, also only 50amp which I believe is original so likely not fiddled with. the only signs of modification I can see is a 0-1 1+2-2 battery switching system.

Dave

Dont forget that not only is an insulating spacer and insulating sleeves and washers for the bolts needed but also some form of coupling between the crankshaft and the gearbox input shaft which will insulate them from each other!

Now checked and discovered that the insulated saildrives came about with the MD 2010/20/30/40 series B engines in 1994