cbr1000fl
50000mi
perfect condition
garaged
new fuel
regularly ridden each week to 2 weeks depending on time availability

the issue
last week starting on the button /running perfect
this weeks first start= a little difficult
idle ok
trying running at higher rpm than idle=> rough/ missing( no backfire )
its as if a plug had fouled ( but idle perfect ) or starvation ( but idle perfect )
fuel tap on
fuel new
3/4 full
battery well charged
have an in line yam paper fuel filter to avoid bits bunging up the jets
what to look for 1st and 2nd?
regs cbppaul

 

I wonder if the bowls have a water mixture in them. I'd try and drain them first thing.

https://www.youtube.com/watch?v=Wrb4pl03xCg

 

found the problem
plug nr 3 had failed
now runs correctly
why the plug failed when at standstill is one of the wonders of the universe
cbrpaul

 

fire a bit of av-gas through it, it'l either kill it or cure it. wheeeeeeelie!

 

Don't recommend AV-Gas. Whats out there now is 100LL, That's 100 octane, blue in color and stupid expensive. AV-Gas octane rating is calculated differently that auto gas for one thing, the other is it will likely trash rubber parts in your fuel system.
It's rare that a plug fails but it does happen. While it may idle fine it can loose it's fire under load. I had very good service with NGK iridium.