jetting issues

[honda250xrider]

can anybody tell me what may cause this, when i jump my quad seems to bog down quite a bit when in the air and when i land but quickly regains itself, and when in between shifts it will bog for an istant but quickly regain itself, i have rejetting went from a 155 to a 152 main, and raised the needle to the 3rd clip, before the needle was on the 4th position and ran great before the weather started to change. I'm not sure but would the air flow screw effect this in anyway?
Thanks,
Lance

[cals400ex]

what year is your bike?

[honda250xrider]

1987

[honda250xrider]

i have tried cleanin the air filter, spark plug, even going down another size on the main, now im almost postive the pilot jet would have little to no affect on this..... my only other theory right now is that i have my timing a little out of wack since the last time i put my engine back together about a week ago, would having the timing a few degrees out cause this boging i feel while shifting and also in the air?
Lance

[cals400ex]

that main jet seems huge. what all do you have done to the bike?

[honda250xrider]

cam, larger vavles, port, high compression, stroked, bored, I know this main jet is not to big, i have ran the 155 for several races pulling very! strong. but after i tore my motor apart and put it back together it seems it likes to bog. tried playing with the jetting but just hasnt solved my problem im starting to think that it could of been caused when i put my cam back in and didnt aline my marks on the cam quite right? i guess my timing could be retarted right now?... im just not to sure what it could be.....

[cals400ex]

i would definatly make sure the timing is right. what is everythign you did while you had it apart? change gearing, cams, jetting, etc??