so here's the story.....

i bought a 87 250x back in nov. and the engine was a complete basket case. i did a complete tear down of the engine.new parts include...
con rod kit
piston and rings
valves
timing chain
oil pump
new cylinder jug(well kinda it came off a 02 300ex)
every single gasket and o ring
decompression setup was completly missing
prob a few other things im forgeting

got it all put back together and it didnt start....big bummer almost gave up.it was getting fuel and it had plenty of compression but kinda weak spark. so i tested everything and evrything checked out ok. coil was off alittle bit but not much.it had a new plug so i ruled that before i even started.
so after acouple weeks of kicking it till my leg felt like jello i pulled the plug out to check something and droped it on the floor and it messed up the threads. so i pulled a new plug out of the box and put it in.....and after 3 or 4 kicks it fired right up and ran awesome!!!! i guess i had a faulty new plug..lol
its 2am and im so happy right now i dont even care that i gotta be at work a 7am.

 

Good thing you dropped that plug or you'd prollly sell that thing. Man, you sure did a lot of work. You're gonna love that bike. I love mine. BTW, how can you use a 300 jug on a 250? The stroke on a 300 is longer. And, do me a huge favor if you can. See how much compression you have. According to my clymer, I'm supposed to have 195 but I only have 170. But it runs great. So, I'd just like to compare it to yours if you have a tester. Thanks Johnboy.

 

the 300ex and the 250x's jugs are almost identical, the 300ex's jug has a breather port i guess you could say about halfway up the jug, i just blocked it off with a large vacume cap. my compression check might not be accuret because i dought my rings are seated yet. i'll shoot you a pm later when i get out of work and check it.