Couple things you can do:

The EHA (Electro-Hydraulic Actuator), a black fuel pressure regulator located on the side of the fuel distributor, can be adjusted a bit richer to compensate for fuel distributor wear, and then adjust the CO a bit leaner. You can also unplug the cold-start valve to see if this helps startup. EHA adjustment is a bit complicated (you measure pressure differential and remove/adjust EHA 2-8 times before you get the adjustment right-on; I'll look up and post the specs Saturday the 25th). I'm assuming a ton of miles (college kid and all...)?

If this doesn't work, give him a 3mm allen t-handle and a can of starting ether for Christmas, and send him on his way for another year.

Valve seals would be a likely cause if it is blue smoke, and enough oil could foul the plugs at lower temps to cause run problems (I've seen it before, anyway, lots of times...). Of course, I've also had them come in needing guides as well, but normally, they give you a rough start when warm as well.

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