Latest update....

Having pulled the engine, & finishing the refurb of the heads, I pulled the rear cover to check the state of play, discovered that the gear change shaft was bent!!

Also, had another look at the cylinder & noticed that one of them had some signs of scoring, (don't know why I didn't spot that before!), so I decided to dig out the other engine that came with the original purchase. That looked as if the previous owner dug it up from a field!!, it looked rough so wasn't holding out much hope.

I quickly removed the heads & checked the cylinders, They were fine, as was the camshaft etc. I'll use this motor then!

 
I will use the refurbed heads from the other engine though.

Today I mostly did..

Tonight I whipped the engine out so that I could start delving into the inner workings!

First bit I removed was the water pump housing...

yeeurgh!! Still turned ok, though I suspect things would have clogged up eventually!

Next I'll remove the rear cover to clean it up & replace the seals.

Today's update

Just a quick one! Have nearly finished cleaning the flakey paint & corrosion off the cylinder heads (what a time consuming jobs that is!!), need to finish lapping in the valves fully, wash then fit new stem seals then they're good to go. Have de-rusted & undercoated a some more brackets. Will take engine out this weekend to clean & replace seals etc.

Tonights bits

Spent an hour or so cleaning up the thermostat housing & connector tubes,

To start with....

ended up with this....

Just need to paint the steelwork & get a set of new O rings, then thats one little job done!!

Progress at last!

At last I've got my arse in gear & done a bit more!!

The engine looks shit with lots of aluminium 'bloom' & the old paint flaking off. So to start the process of re-juvination I took the heads off.

Found snotty gloop in the left hand cylinder water jacket...

Bit of judicious use of various scrapers & compressed air seemed to do the job...

 Spent a couple of hours on the head to go from this...

 ..to this...

the valves require a bit more grinding in before replacing valve stem seals & giving a final scrub, don't think I'll bother with porting, not sure if it'll make much difference.

Need to do the right hand head, then will remove engine from frame to delve a little deeper!