hi i have a 2000 ttr 90 just had it bored up to a 110 and put a fresh top end in it well after i got it all put back 2gether i got it to start and it ran for a second then just instantly shut off. it still starts but just wont idle or anything it will run if i give it throttle but dies otherwise and it blows smoke out the exhaust and i know thats normal till the rings seat but this is my first rebuild so not really sure what to look for

Any mods done to the carb after top end rebuild? You will at least require different jetting if using the stock carb, if not having to switch to different carb all together. I'm not familiar with this bike or the mods but if u haven't done anything to the carb/jetting to accomedate the increase in displacement you most definitely will have to change it to run right. As far as timing if it is like it is on the 125 then there are two round covers on the left engine case above the shifter... One big and one small, you have to remove them, the big one allows you to turn the crank and the small one is a site hole with an index point for TDC... Also you have to remove the side cover for the cam sprocket on the cylinder head.... With the crank lined up at TDC the cam sprocket has a mark that should be lined up with the index mark on the cylinder head... Don't know if this will help but if this is like the 125 and it is all lined up you know it's timed...

Also what color smoke? Oil smoke should clear up pretty quickly after it runs for a min, if it contiues to smoke continuosly the the oil control ring probably isnt installed right. black smoke means its running to rich...