Sorry I have been somewhat inactive for a while - various problems laid me up a bit. Anyway - to conclude the outboard saga !

I managed to get an oversized piston and rings from Seamark Nunn a while back. The spare casing was badly worn on the bore - so needed reboring.

Come start of the 12 season, after a year doing nothing I at last dug out the dingy and inflated it in the garden - all ok there. Pulled out the engine - a quick look at the casing repair and I instantly saw 'growth' - evil alloy swelling growth. A poke with a screwdriver and my repair fell off ! It had lasted really quite well.

So - rebuild yet again. Luckily I kept my flywheel gadget I made - but had to remake the holding stick. Whipped it all apart - and now used the spare engine casings and bore ( re bored at a local motorcyle workshop - 'Piston Broke' , thats a great trading name ! )

My super new machine is now all blue - new piston, rings - rebored. Wham - first pull, it goes. Just a run in now on 25:1 for five hours running.

Its been a long saga. One thing I could have done - that is not to even try to contain the water around the jacket. ie - if I had put an open pipe in the end of my patch, the leaking water would have at least been controllable - ie not spraying all over the engine casing and shorting things out.

The problem with these water jackets is they do not drain. The main jacket fill from a hole at the top of the head gasket - and the water enters and leaves at the base of the head gasket ( head and bore are horizontal ) Only the head drains in the vertical postion. The only way to drain the main jacket is to repeatedly put it head own - then upright again, This fills the head ( small space ) which then drains when in the normal positon at its base. Then again and again. I'd say the head is 10% the capacity of the main jacket.

Difficult to fit anything over the inlet slots to attach a hose - but not impossible. Probably easiest to just take the head off every three months and check the jacket for build up of salts. Trouble is - head gaskets are £11.00 now and you usually have to send off for them - and they are the sticky kind. Taking one off you damage it a bit. They may go back on with something like Wellseal - or just red Hermetite.

These are great little engines that would go on for ever if you could sort out the salt water/ water jacket problem.

Why - why why did they not anodise the engine casings !!!

Note -

Apparently, I've recently learned some early engine casings were put out to a third party and of lower standard alloy. Also - they were zinc chromated inside the water jackets. While my jacket was pretty clean maybe I should have done that ?

I've got on the habit now of running it in fresh water for a while when I get home - does not take long to do. Adds to a bit of running in time. After three return trips up the river it seems fine - though my filler cap and vent all fell to bits for some reason. Luckily it all fell into the tank and I could fish it out !

Anyway - I now have an intact engine !

Hopefully....

July 2012

............

Update - April 2013

Still going strong !