Weird hiccup during engine braking

[outerspace]

The bike is a CBR F4 (in other words, carbureted).

During engine braking, the bike kinda "hiccups"... dunno how else to describe it.  Like it sorta bucks back and forth a bit...

When I am:
- decelerating to a stop in 2nd or 3rd (sometimes 4th) gear
- very light on the brakes (or no brakes; engine braking)
- roughly about 5k or 6k RPM

Only happens maybe once a day / once per tank, but if it were to do something like that in a corner it might not be good.  :[

Ideas?!  Checked my chain tension already, and I have been making sure that I'm not on throttle when it happens.  Sorta sounds and feels like the fuel is getting cut intermittently or something.

[Paradon]

Have you checked the fuel filter? Could be a blockage.

[Ataylor0]

Possibly a blockage in a fuel line.

[outerspace]

No problems at idle or on throttle, tho; not even WOT.  I would tend to think fuel line blockage would be a bigger problem when more fuel was needed.

[DarkNinja75]

My F3 used to do something similar. Going through turns it felt like the throttle shut off for a split second, then went back on. I took the carbs apart, cleaned and adjusted them, and that fixed it. I just don't know why.

Another option is misfiring. I've driven a car that did this. Under steady throttle or acceleration, it skipped a bit. One of the spark plugs wasn't firing, which could've been caused by either a bad plug or bad wires.

[turtlemann14]

could be caused by an air leak as well. you hut the throttle fuel delivery slows down and due to the higher vaccume more air is pulled in though the leak leaning out the engine past the point that it can run.

check your carb boots for leaks.

[ilanidrac]

I agree, check the carb boots for air leaks, and maybe even run seafoam through the gas to knock out anything that could be gunked up.

[outerspace]

Good ideas!  Thanks guys!

[dragonoth]

sounds like a timing problem. dont try to ride throught it. take it to a shop and have them check it out or you might end up with a bent valve

[Wever1988]

This has nothing to do with your fuel lines.
My bike does it sometimes aswell, it's either a misfire or a timing problem.
A airleak could also be the problem like turtleman said, but I do not think that is your problem.