Hi all, i'm new in this forum, and just bought zx6r '96 - it runs fine, except starting from 3rd gear when I cruise ride it at around 40mph, it runs like coughing..like it's loosing power, if I throttled up, it will rev up but surely it's not smooth and uncomfortable to ride...
When I wanted to accelerate hard, then it always kinda loosing power when I shift gear up... stalling...and then rev ing again... really not very comfortable...
Anybody experience the same condition? or maybe somebody can tell me why this' happened...and some solutions will be perfect.. Thanks a lot!!

 

higher gears put more load on the engine so it will bring out problems like bad gas (water, or low octane), bad spark (plugs, wires, coils), and other issues.

I would start by check the spark plugs and then adding some dry gas to the tank to get rid of any possible water.

after that i would be looking at the carbs

 

Mine randomly doesa similarthing. I strongly believe that having the carbs sync'd and cleaned will take care of that. Mine stumbles at cruising speed.. When I get on it she's fine.. I am going to change the fuel filter, and have the carbs syc'd in the fall...

 

Sound like water in the carbs. Drain the float bowls and put some RXP (Autozone)in the tank. Cleaning and synching the carbs maybe a good idea if that doesn't work. It could also be electrical. WHen was the last tune-up/ spark plug change?

 

I really didn't know when it's last synch and cleaned As I just got it for a month...

I changed the fuel pump because i saw that the suction is very weak..but still the problems are there with running....ow I also change the airfilter to KNN airfilter.
It runs like crap now... cannot run more than 40km/h, well tried to open the choke and it showed better performance, it ran to 60km/h... thought this is Jetting problem..Lean problem?? well..i can try to throttled it up when it started coughing, and sometimes it will rev again...but most of the time, it will sounds heavy in the engine... Gosh...felt like riding a bike now

 

Forgot to answer, I have changed all the plugs too...thanks a lot!!

 

You may need a jetkit. If you get one, get a Dynojet Stage 1 or 2. Sounds like it's running lean if it got worse with the K&N. Was it always running like that or did it start all of a sudden. If it runs better with the choke on, then it's definitely running lean. What's the history of the work & mods done on the bike?

 

Thanks on the info, i'm ordering that dynojet stage 1 kit now... How's the performance with this kit?
As far as i remembered from the day i took the bike, it's been like this but before it could run and rev up to more than 120km/h... I guess the previous owner didn't take care of the bike well, i took it on advise of mechanic that the engine is still in great shape... It used a sponge for the airfilter before I changed it to K&N -you can see what i meant by the previous owner not taking care of the bike - and I didn't know about the jetting inside the carb...Guess it's already been changed to smaller than standard jetting.
The other things on the bike is still standard...

 

Remembered now, that before adding the sponge filter and changed the jetting, the previous owner said he got the bike tuned up all wrong by dumb mechanic, the mechanic drilled / make the jets larger than standard, and remove the airfilter..said to make the bike faster...the result was the bike ran like crap... And from that point everything seems to degrade the performance...
I hope it will runs great again after installing dynojet kit later...

 

dumb mechanics drilling carbs makes me think you may be looking for a new used carb soon