Originally Posted by Dino89
if anyone has workshop sectional picture showing the assemly of this shaft woould be useful
I do, but I'll have to get a pic to you later when the camera batteries are charged up.
There's no speedo pickup on pre blueband model 500's.
The main driveshaft on these usually has a fair bit of movement up/down on the splines into the drive gear of the lower unit-about 10mm in fact. This is why I suspect that your driveshaft is siezed to the powerhead. The driveshafts on the red bands weren't stainless-they just had a plated area round the lower unit seal
unlike the later bluebands.
This is going to sound odd, but what I'd do is turn the engine upside down on a flat surface (make sure there's no water in it 1st),block up ALL the holes that aren't in the lower unit(carbs, plugs, peehole, exhaust transfer port) and pour a gallon of diesel straight through the 10mm gap in the lower unit. Leave it for a week or two for the diesel to penetrate, maybe tapping the chocks occasionally while you wait to see if it pops apart.
This sounds loads more sensible when you bear in mind the manual seems to think the only way of seperating a siezed drive/crank joint is to drill a hole in the leg and then cut it with a gas-axe... There's realistically no easy way of dealing with a 40 year old engine that's got stuff siezed in it
Assuming it comes apart, make sure all the diesel has drained out of the engine before you try and turn it over or it'll fluid lock.