Jetting/filter/airbox all OEM? If so, then "could be" a weak spark, if load causes it to stumble.
RAM air is a pain when setting up the carbs, but yes, seems we were heading in the right direction with this one. Just to remind you, the main jets on 2 and 3 are supposed to be slightly bigger, due to these cylinders running hotter. If the jets were the same as 1 and 4 then 2 and 3 would run lean, hence the difference.Hello everyone,
So... it was a airbox issue with air leak because a vacuum valve was not set up correctly.
Basically on this bike there is a pipe running from the carbs to the top of the airbox. This pipe helps the bowls to get 'pressure' from the airbox running as the vaccum created in he throat of the carb is not enough to get all the fuel out. I do not recall a deisgn this way on the EX where the air box is plugged to nothing besides the crank case vent... apparently it is a ram air design so different from the EX with this additional pipe.
So plugged it in and it all worked.
Then ran the bike and had issues at 9K rpm exactly, turned out that the air filter had way too much oil on it caused trouble.
Also figured out that the main jets on cylinder 2 and 3 are bigger that those on cylinder 1 and 4!!!!!!!!!!! As opposed to the EX where you dont have to pay attention to this detail.
So bottom line these things are extremely sensitive lol, it was a nightmare to figure out but now all good! Thank you.