250F why does yzf250 start and stalls?

[marvin39]

Goodmorning people....i bought a yzf250 2005 (its my 1st fourstroke)that was sitting for about 6months .the owner told me that cylinder needed to be changed .ok i changed it (but the shop sold me an bigbore athena 83mm by mistake)an serviced the top end and valve adjusted also .cleanded the carb .put on a new spark plug cr9eix iridium ngk .put on a new athena airfilter .now after days of kickik the bike he finally started but stalled right after a few seconds ....now he is starting after a while of kicking (30minutes at most ) then he idles high and stalls again but then still start hard(difficullt).. .what could be the problem?

 

[bobkyle2]

Check valve spec's, Go back through the carb.

Also, Dump the fuel and add fresh.

 

[marvin39]

Already did that but will do it again....what about the sparkplug? Do u think i bought the wrong one ? Reminder ..the feulscrew underneath the carb is also missing the small washer and o-ring ....Btw thanks for the reply

 

[marvin39]

Do u think that if timing was 180degrees off it would start? Cuz in de beginning it was backfiring but it stopt and it also not bugging .and when it starts it idles high and stalls like ur using the kill button

 

[timoyz]

Already did that but will do it again....what about the sparkplug? Do u think i bought the wrong one ? Reminder ..the feulscrew underneath the carb is also missing the small washer and o-ring ....Btw thanks for the reply

That would be a major problem right there.