Got this 1990 KLR 250 from a friend a few yrs back , it ran fine for him before it developed an electrical issue , it still ran , for him, but the head lite
wouldn't work. I traced
hd lite issue to high resistance grd/neg connection internal harness , multiple wires crimped together inside harness connect multiple
negative leads.. I also discovered that harness carried much of GRD circuit, not chassis. I connected a grd wire to chassis at battery and
also all wires behind HL , color code BLACK w Yel Stripe. This fixed HL and also the odd condition that when KILL switched was switched to OFF
instrument lights got brighter. ( hmmm i need to recheck drawing for factory connection of chassis to neg battery ...I assume its there could
the chassis be floating?? That would be ODD))

BTW the schematics had a misleading symbol on KILL sw...it connects the AC lead from stator ( for CDI power) to battery NEG to turn off engine.
The CDI is powered off AC current from stator winding. It should not need 12v from battery to start, but I have a good battery and am getting Spark.(after some work)

After HL fix I turned attention to Spark. I was not getting any. I tried another CDI ( NEW 650 see below) and still nada. I hooked up a
china DC type CDI got nice spark.
Tried to start it , nope. Even with quick start. I thought perhaps the china advnce was wrong so I looked back fixing orignal CDI system.

After reaserch I realized the diode package used to "sum" KICK Stand, NEUTRAL and CLUTCH switches was missing.
Seems my friend removed in his efforts? Not sure how that happened , but I tied those 3 wires to grd at the connector body for missing diode pak.
After doing that I got spark using NEW CDI for KLR 650 that I obtained on EBAY.

It was $10 less than the 250 version and a check of the schematics
indicated that the extra wire for 650 ( single connection, YEL w BLK stripe) was connected to the starter relay.

I suspect it provides a "hotter" spark on the 650 as battery voltage sags during cranking? Regardless that wire was not energized during normal
running so I got one. I taped up that wire as I only hav kick starter. I do believe the 650 CDI will work fine ...but will know for certain if I
c it run with it.

After the diode bypass to ground I got spark from the new 650 CDI system. But still not one bang , even with ether.
I removed carb so I could shoot ether directly into intake ..still not one bang.

I tried the original CDI, which now gave spark with diode bypass implemented. Still no bang with ether in the intake.

I removed valve cover to observe vales and could see the compression release mechanism. It seemed free moving and not sized.
The valves were moving up and down fine.
It seems to have compression as I can tell from the kick starter resistance
I might move on to compression check, which will require a new adapter for my tester, but maybe I missed something ??
Fuel , Spark and Compression? Could the timing have slipped?? timing is set at crank mounted magnet anyway...not sure how to check timing on this engine.

Suggestions?