J.A.P. with Pegson pump

I recently won this on Ebay for a great price. Despite the pictures it was pretty much complete and I've been stripping it today.
I've got to a point where I can't carry on and I wondered if anyone had any ideas. I can't seem to split the engine from the pump. I'm guessing it is a parallel shaft but could it be a taper? Or is the impeller threaded on, if so is it a right hand or left hand thread? The starter dog was a normal right hand thread.

Here's some pictures, see what you all think.

Looks great, what colour are you going to paint it? any idea on age?

It was green but I fancied a change, I've got some post box red or some building site/plant orange. I was thinking about shining up the ally on the pump with an oily rag as well so most colour would be for the engine and petrol tank. It's a lovely little unit, the magneto looks to be in fairly good nick as well.



No idea on age, the engine plate has had it so not even sure if there are any numbers on it and the pump plate went a long time ago by the looks of things.

Here's a link to the original Ebay listing, I forgot to take any before pictures

http://www.ebay.co.uk/itm/JAP-2A-four-stroke-petrol-stationary-engine-Pegson-Water-pumps-nice-exhibit-/121147727162?_trksid=p2047675.l2557&ssPageName=STRK%3AMEWAX%3AIT&nma=true&si=nsV9gosldleCRnwcruQE4YkNkEM%253D&orig_cvip=true&rt=nc

Is that a grub screw on the raised part of the casting that joins engine to pump? I bet the pump shaft goes over the crankshaft and its keyed and possibly grub screw too, although maybe just a press fit.

Ian I have a similar unit but the pump is an ALCON.  The impeller on that was screwed on, standard right hand thread, and unscrewed easily after a tap with a hammer and piece of wood on the end of the scroll.  Behind it was a spring loaded seal.
 
Pete.

I don't remember seeing a grubscrew on there but I'll take a closer look before I try unscrewing it. There's a lot of crud on it and the light is terrible in my workshop but at least I've got a bench now. It's good to be able to do some work finally

Thanks for the suggestions

My Villiers/Hippo pump units had screw on impellers as well, one I managed to un-do by hand quite easily, the other took a bit of shocking off.

Bring it round here if you like, I've got the Scott running now so the bench is relatively clear (for now at least).

Pete, you were bang on mate, cheers

Pump and engine now separated and crankshaft out. There is a fair amount of play in the big end so if anyone knows of any spares knocking about I would be most interested.

Now there is a lot of cleaning to do

Cleaning in progress yesterday.

Foden wrote:Ian I have a similar unit but the pump is an ALCON.  The impeller on that was screwed on, standard right hand thread, and unscrewed easily after a tap with a hammer and piece of wood on the end of the scroll.  Behind it was a spring loaded seal.
 
Pete.

Exactly the same setup as most modern commercial dishwasher pumps