Fresh top end has a bog that clears??

last night put a new top end on my 670 summit hoping to break it in at starlite this weekend , but I have a low end bog that has me confused the idle is a little rough the spark is great #1 pipe hot #2 pipe not as hot, compression equal,fuel fresh, carbs clean,but when you throttle it bogs out until you give it a shot off the primer which brings it back to life once off idle it works well. is it running to lean? or is it the carbs need synced( how do you do that on the cheap). If you read this please give me your suggestions or ideas I need a sledding fix instead of fixing sled.

the RV great idea

which way would cause that advanced or retarded?