250r kills hard??

[yeppimcody]

airfooler i just rebuly my 84 250r and was riding it to night had to rebuld it because it leand out but any way, it had a jet in it No. 310 so i bought a buch of jets i put the fattest one i got a 540 in it. well any way i was riding down the road at about 3/4th throtel and i just killed hard like i hit the kill switch (witch i did not) i kiked it over started right up no problems i was riding it a round babbying it then i gave it 3/4ths and bam dies agin. i pulled the brand new lug out and it was flat black not wet black?? so i dont no if it was too rich or the istons not broke in so it causes it to kill of my jets wayy to big??? :wondering thanks in advance.

[RodKnockRacing]

310 and 540 thats crazy assuming your talkin about main jets

[yeppimcody]

well i just rebuilt it and i dint want it to lean out id rather fowel lugs then have it lean out and dum another 200 in to it.

[yeppimcody]

i am talking about main jets but is a flat black plug chop to rich or to lean?

[fabiodriven]

A black plug is too rich.

[yeppimcody]

evean if its not wet oily black?

[AutoXer]

you don't go from 310 to 540 that is way too much of a jump. If it was lean and blew it was probably getting air from the low end or intake. Try 2 sizes up from 310