'83 honda atc 185 new engine issues

[ihatestuff]

just put a new engine in my 185s. wont pull start whatsoever, so i had my buddy pull me down the road. it will sputter and backfire like all hell, so it has spark. i threw the carb on a fat cat i have sitting underneath the porch and it fired right up. could it be the valve timing? if so what do i have to do to fix that? i have minor experience with this stuff unfortunately. i just bought my first three wheeler like two weeks ago and now this is my third one. im hooked.

well i figured i would try and ask on here, thanks.

[Kale]

Did u rebuild the engine yourself? sounds like a carb problem to me tho. jetting not quite right for the setup? air leaks in the intake? What does the plug look like? have you pulled it and visually checked for spark? is it wet?
oh, welcome by the way

[RodKnockRacing]

Could be a number of things carb problem like kale said, or timing whats the compression like?