Hello and welcome,.
Firstly try a little punctuation and grammar (like it is now).
Secondly, indeed there is no fuel pump on the NSR250.
I presume you're kicking it over on the kickstart? You're asking a lot for it to go if it's not run for a long time and has just been chucked back togeather. You might have more luck if you try bumping starting it, preferably down a slight hill so you can let it turn over few times. You'll also be able to feel if it's trying to fire at all.
Not that any of this is a good idea, you should really put it togeather properly first.
Don't forget to put some decent 2 stroke oil in the autolube system and bleed it through if it's been left dry. Or just put some in the petrol at a ratio of 30/1.
You might want to try check the battery too, they start a lot easier on a good one.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread