Something is gettting missed in a big
280 kind'a way, here.
1. WOT on compression test.
You bet. The point is to determine how well the engine compresses the intake charge....NOT how much air you can squeek past a closed slide! Open it up!
2. (shoulda been #1)
280!!! main???
This has to be a mistake!!! Tell me it's a typo.
From CDave's site:
1989 to 1994 KDX200
Stock -Run the stock R1172N jet needle in the second from the top clip position, 48 pilot jet, 155 main jet and fine-tune the pilot circuit using the air screw.
Even WITH a typo (if it is a 180, not a 280)...your carb is way out in left field. The pilot is also so far out of whack...it's a wonder the thing runs at all!!!
BTW...on the 'running' part. You described the bike as 'not being able to get out of it's own way' (as I recall...didn't go back to page 1 to check). Is it 4-stroking when this is going on? Blubbering and smoking?
Plug color really doesn't have much to do with anything except when used with a WOT plug/chop test. Doesn't seem that's happening, yet.
I go back to when you leaned the needle (dropped it), and things improved. You've got to, absolutely must, please!! get the jetting sorted out!!
Yes, by all means keep at this problem. It's fixable. Don't despair over it, keep at it (as woodsy said) and you'll get it.
But
DO read the suggestions.
IF the 280 number is correct...this could have been resolved a long time ago!
Please repost with the numbers of the jets you have (no typos twice, please;) ). If your numbers are correct...get the jets CDave recommends. Change 'em. Let us know what the result is.
3. 20:1? Was that a joke? 32:1 is generous, plentiful. 40:1 is good to go unless you are SEVERELY screaming this bike (constant pinned throttle, sea level, big-time load.....like on the dunes maybe).
4. I'm sure there is a #4...but...what was it??? ;)