break up 6k

Lost for words lost on start.

OK fast fill in over winter rebuke carbs so on. This spring colder weather ran good good sync and so on.

Hot weather 80 + my bikes breaking up on have needs but will regain power an speed above 7k.

It will go past 6 k no issues if your running 12 gears 3 and on is where its under a heavy load and I becomes gutless around that 6k mark.

Thinking about a re sync but then a cold day come 70 or so an it ran fine.

Put it on a super fast plug read ( not a tune just pulled plugs ) and that was just burn with a light hit miss black tell me is running a hair rich when is cold but over rich when is hot. After a retest on hot day.

I'm lost on what's wrong where to start or why weather will play a big part in it.

Well any help be thanked (yes all tunes and shims was done 300 or so miles ago so don't think that's my problem) but who knows

 

hot air is thinner, thinner = less oxygen, less oxygen with the same fuel = rich.
does it run good before it gets fully warmed up?
lower the floats or turn in the mixture screws a wee bit

 

What plugs do you have in?

 

My brain hurts after reading that...

 

Mine too.

THROTTLE SHAFT SEALS. (Provided everything else was indeed done correctly.)

Have at it.

(Or you didn't really get the carbs clean and the emulsion tubes are all clogged up or your float levels are wonky.) But, if you truly did everything else right:

Throttle shaft seals. Unless it's ignition related. Did you crop the leads, tighten the resistor cores in the caps, etc?

 

Yes It runs great cold and for the 1st 20miles of a ride then it goes south. Unless like I said cold day. I'm running the stock ngk plug it called for and yes spark test(volts testing so on is fine) I went and took the bike out today and its got a idle problem now running super lean. Starting to think I might of got a sticky float but all 4?

Shaft seal how would it act?

Thanks for the help so far and sorry for bad writeing blame my touch screen phone not me.