Troubleshoot Bike Not Starting

[wardd]

I'm looking for some help from those more knowledgeable than myself.....

Just replaced the top end, repacked silencer, cleaned carb, cleaned throttle, and installed new aftermarket reeds in my 2001 YZ250.

Problem is, now I can't get it to start. Bike has always been spot on, and started with no throttle, choke, on first kick. Wanted to do the top end before ArenaCross.

There was a good article in a past 'Motocross Action' mag on steps to check if bike will not start, but I have misplaced it. Can anyone suggest a sequence of steps??

Bike seems to have decent spark, and has very good compression. However, it just will not fire. I've also tried spraying starting fluid in the air cleaner, but to no avail. Next, I was going to remove the float and verify there is gas in the bowl.

I'm sure everything was installed correctly, because I was very particular and took my time. Very frustrating!!!!! I've been kicking so many times the top of my foot is taking a beating from the peg.

Please help! Don't really(and can't afford) to take it to the Dealer.
Wardd.

 

[wardd]

Got it!

Ok...., so I could not go to sleep until I played with it alittle more. Figured it out before anyone could reply it seems. Good lesson...... yellow spark, BAD. Blue spark, GOOD:D ! Never assume that just because a plug is new that it's good, no matter how many you try.

Wardd..

 

[David Trustrum]

Once a plug fouls it may not recover properly. Out in the open it may spark well but in a combustion chamber may just foul up again.