Interesting, I have a 998 in the shop that has been driven to the state inspection each year for the past six years and not much else. Pumped the fuel out and replaced with what they call gas now. Pulls nice up to 3000 RPM. Tends to lunge in each gear above 3000. The exhaust tip looks to have been running rich for awhile. It is a HS4 waxstat and I have not checked anything yet. Will stick O2 test tube up the pipe and have a look at what it's doing. I did not even think to pull choke to see if rich at idle and leans out as it goes. Steve (CTR) 

Checked/changed/adjusted most everything on the list, but it turns out the problem was solved by simply replacing the in-line fuel filter!  Thanks for all the suggestions.  It's SO great to have this much Mini knowledge at our fingertips.

Replace all the items you list. Its time for a tuneup.

Too lean a mixture for the given load will result in a "skip" as you call it!  Test my theory by down shifting when it happens!  Also the 998 simply does not make that much power.... most are lucky to put 22-25HP to the wheels, so careful attention to load and RPM is required for smooth operation!   If you are doing 45 MPH and the conditions (such as slope, wind resistance, how many large friends you're carrying, what gear you're in, what final drive ratio, and so on....) require 19.2HP to maintain that rate, and your engine is making 19.1 at the given RPM, It will stumble! Down shifting will let it clear it's throat and pick up revs where it can make more power!

The short answer is "yes".

• First, check air filter is clan and good. Replace/clean as needed. Check dashpot oil level. Test-drive to see if this has solved it.
• Remove spark plugs and inspect before cleaning. Beige or sandy coloured light deposits suggest good tuning. Very light black, dry soot may be just  because you switched off the engine and the residual burn wasn' complete. A full black coating suggests rich mixture or poor combustion.
• Clean plugs or replace if electrodes appear worn. Gap new or old plugs to spec. Don't trust the 'as new" setting.
• Inspect distributor high tension wires, boots and connections. Clean or replace as needed. Dirt on the outside can cause spart to leak away. Some people swear by WD40, but I think it eventually collects dirt. I prefer clean wires.
• Inspect dizzy cap inside and out. Look for dirt (see wires above), cracks chips, or spark 'tracks'(inside) where spark leakage has traied off the terminals. Check the inside terminals - the 4 'plug' terminals should be clean but may have a crusty appearance from metal transfer from the rotor. (Spark will carry molecules across the gap.) Note the rotor does not touch the se terminals, but the spark jumps as the rotor just swings by. A light coating is OK but of it is heavy or the terminals are damaged, melted or corroded it is finished. The central terminal should also be in decent shape. It presses on the centre of the rotor, making contact. Replace cap if you see any of this.
• Check the rotor for cracks or spark trace, and the condition of the centre pivot point and the end terminal of the arm. The outer terminal can be polished up along its edge with a fine file or emory paper.
• Check points: Inspect the contact faces that they are smooth and even. again, spark here (12V in this case) can cause metal transfer each time the points open, sometimes forming a tooth on one face and a corresponding pit on the other. Replace if necessry.
• Check the advance plate rotates under finger pressure. The springs are stiff but it should move smoothly. Check also the vacuum advance is working (suck on the tube and the plate should shift).
• Regap points. The contact that rubs on the cam does wear down, reducing the point gap and the 'dwell' (how long the points ar held open). Using feeler guages is the traditional way, but if you have a dwell meter, it gives better results. The feeler guage method assumes the cam of the dizzy shaft is not worn and is to the right profile. The dwell this way is an estimate based on original geometry. The dwell meter mesures the actual extent of the time the points are held open.
• Reset timing. This is dependent on the idle speed and spec of the motor. Idle and timing need to be rechecked as adjustment of one affects the other.
• You may have to check idle mixture for a smooth idle. but it should NOT be very far off. Note this step is last.

If this doesn't solve it, then think about carb isssues.

Minis with points-type distributors generally need the ignition checked 3 or 4 times a year, depending on use. Usually the dwell and timing are off a bit and the rest is OK. Somethign we've forgotten, driving our electronic futuremobiles.

Dashpot oil level? It's EZ to check.

I've noticed my 998 is beginning to skip just a bit under moderate to heavy throttle.  Where should I begin to look for the solution?  Distributor cap? Rotor? Plugs? What shoud I be looking for?  Thanks.