Power surges at WOT

[Gt_drummerdude]

Hey Kat people, I'm new. Im pretty mechanically inclined so feel free to be technical in your reply. '96 Katana 600. Runs great, just a little cold blooded. When totally warmed up it has a high rpm power surge at full throttle. Feels like ~20 hp coming in and out and it's driving me nuts. I decided to do a street fighter conversion and tonight is the first time I rode it since removing the fairings etc and it's worse tonight for sure. But I also filled up with gas right away, and it's possible I got watery gas? It was circle k after all... Other than that, what could cause this issue? Also, does the choke on this engine block airflow to pull fuel in? Cuz even at full choke the bike doesn't seem any slower than with no choke at WOT....

[92xjunker]

Slipping clutch. Does the rpm spike during a loss of power?
K&N air filter will cause surging also.
Fuel filters installed on a pre 98' will also cause surging.

[Gt_drummerdude]

No clutch slip. It has a foam filter. Looked clean without taking it out. I'll probably replace the plugs tomorrow for good measure. It does seem to pull smoother with choke fully engaged. Shouldn't that restrict airflow and make it slow though?

[92xjunker]

ANY HIGH FLO FILTER ISN'T GOING TO WORK WELL AT ALL RPM RANGES. Install the stock type filter and she'll run better.

[Gt_drummerdude]

I figured foam was stock lol what is the stock one paper?
Is the choke just a fuel enrichment circuit in these carbs or does it block off airflow to pull fuel in?

[shpielers]

Choke is an enrichment circut, it adds more fuel. No airflow blocked. +1 to oem style, and yes oem is paper.

[Gt_drummerdude]

The bike also had a dead spot at like 30-40% throttle that you could throttle thru but it took a sec. Stuffed some tissues inside the air filter and the bike runs great. No more issues. Im ordering the stock air filter. Cant believe how much of a difference a filter makes.