94 KE100 needs a fresh spark plug every start.

Warren3200gt wrote:

Drain the autolube dry and run it on  premix to see if the plug still fouls with a reasonable mix ratio of 30:1?
Is the plug heat range correct? 
Does both the plug and cap have resistors in causing a weak spark? 
Don't do oil burners myself but just suggesting stuff. 
🤷

I'm using NGK B8ES plugs. (they are what s recommended) Also tried a couple hotter B7ES.
Wouldn't running with the autolube dry damage the oil pump?

Wouldn't have thought so for a short period. I would think the pump is lubricated by gearbox oil not 2 stroke oil at a guess. 
Definitely using B8ES and NOT BR8ES? 
B(Resistor)8ES.
As I said I don't do oil burners but would think only mix ratio, weak spark or to cold plugs could oil them badly. 

Is it possible to back the oiling down to factory spec ?

Wookie58 wrote:

Is it possible to back the oiling down to factory spec ?

The only adjustment described in the service manual is pull cable adjustment that comes off the 1 into 2 throttle cable. There are adjustment lines on the oil pump lever that are adjusted to line up at the point the carburetor slide starts to open. I have that adjusted to spec.
I'll be off line untill next Wednsday. Going low tec on this Mid Ohio trip. Thanks everyone for all the suggestions. I'll get back to this discussion then.

I am assuming the plug "gap" is correct - a plug won't spark if the current has a path to ground which is easier than jumping the gap (electricity is lazy !!)

yes gap is correct.
My use of the bike at mid Ohio went well. The spark plug fouled out mid day Friday This time I replaced it with a new NGK iridium plug. That one plug made it through Saturday and Sunday.
Before leaving on the trip, backed off the oil pump lever cable adjustment just a hair. Also replace the #80 main jet with a # 77.5. So, leaning out fuel and oil slightly and going to an iridium plug helped.
I checked compression when I got home and got 150 psi. The service manual specs are 139.5 psi with a service limit of 98 psi. Can high compression foul plugs?

No compression won’t cause fouling however the higher it is the harder it is for the spark to jump- try closing the gap a “little” and see if it helps 

Compression is one thing but have You, as suggested, preformed a lower-end leakdown test yet? These are not 4-strokes so 2 tests are required. Also i ALWAYS replace the choke plungers on these. Note your style shown. Also look down the casting where the plunger goes, is the "proud" seat pitted or messed-up? I do a lot of the Suzuki TS T250-305 and super-six-hustlers etc. Check this stuff!! It's the road to success! Gotta Open that door and quit running into it. Also, though Highly regarded by many folks. Don't replace this plunger with a Keyster Brand!! I've seen several that the pad just falls out of them.They are NOT crimped like the original, just glued. And final, make sure you adjust the choke cable correctly so plunger seats fully with a bit of freeplay. Have Fun!     

Another consideration, Float/Float Needle Seat. They made a gazillion different type floats for these little Mikuni supplied bikes. Make sure Your  floats and doesn't sink. You can rattle it close to your ear and hear the sloshing if "often" pin holed/rotted thru the brass. And..Float needle seat and needle. While might seem fine at first glance, is it actually doing it's job? Does the compression pin on needle have strong/decent "springy" action? These are buzzy little machines and the sealing can suffer from such activity.   

A little late here but let me gently suggest that you need to rebuild the lower end to replace the crank seals.  They are over 30 years old.  The lips on the seals are almost certainly somewhat brittle by now and if so they are leaking crankcase oil into the combustion chamber.  The definitive test is a case pressure test/leakdown test but I wouldn’t even mess with it in this case.  From having rebuilt a lot of vintage 2T lower ends I guarantee you the seals are partially dead.  When the seals totally give up the ghost, the bike will smoke like a mosquito fogger.  Plus this will give you the opportunity to refresh all the other lower end consumables: bearings, seals, clutch plates.  The bearings and seals are all standard over the counter metric seals and bearings, available everywhere.  

Special tools you will need are a case splitter and that can be worked around by using a loaner puller from autozone, just have the get the right one; also need a clutch basket holding tool, large socket for the nut on the primary gear, and a 1/2” breaker bar for that socket, or an impact wrench.   If the case screws are stuck you will need an impact driver to remove them.  

Good luck!  I’ve rebuilt many a 2T lower end.  Just follow the manual, mark all your case screws so you know where they go, use some wire to wire the transmission shafts together before removing them from the case, and watch out for any thin thrust washers on the ends of the transmission shafts and kickstarter shaft.  Take your time and go slow is the most important thing.  

 Other super helpful thing is to make an engine holder out of 2x4’s.  Just Knock together a small box out of 4 pieces of 2x4 that is approximately the same size as the engine case, maybe 10”x12”, then set the engine inside the box.  I cant tell you how much easier this will make the job.  I can make a sketch if you need it.