When you say stock engine, I guess that's the 3-port?
That's what's come with them for quite a while now.
Here's the instructions for that engine which has the factory base settings in it
http://www.cmldistribution.co.uk/dia...%20_3-Port.pdf
Just note that those settings are for a brand new engine and are very rich.
So as the engine your mate has got will presumably have had some running it will likely be too rich by a reasonable amount - but it's probably the best place to start.