Air filter recommendation, 2000 Model E1 ZX9R

[maraach]

Hey guys,

I have a full yoshi rs-3 system currently on my 9, and have had it rejetted (apparently the jets are 2 sizes up from standard - not that i know what that is - it was done before i bought it :S). I'm beginning to think the bike may be in need of a tune (although it was done mid last year) as i'm having some problems with it - starting when the bike is hot can be an issue, especially if i try directly after filling it up at a petrol station (running rich?). It's not terrible, just takes a couple of attempts and some playing with the throttle to get her going.

Another thing i have noticed is that at low speeds, especially when its cold, the bike has a tendency to surge if i'm not on the gas (running lean?). After its warmed up its less noticeable, it's just a pain as i have to ride down a super slippery pebbled driveway with lots of blind turns and old (read: don't pay attention) neighbors doing there best to kill me. It's really only a problem when it decides to do it in the bends and tries to play the rodeo ride with me.

Anyway, before i proceeded to try and get it re-tuned someone recommended to me that i should probably switch out to a hi-flow air filter if i'm running a full system with a couple jet sizes bigger. At the moment i'm just using the stock Kawa one. I was just wondering if anyone had any opinions on this (whether it's a good idea or a bad idea) and if so if they could recommend a filter to use. I pretty much only know of K&N but a lot of stuff i have read recently has stated that they aren't as good as they once were and are now living more off their previous good brand name rather than their filter quality.

[kwakamad]

Bmc, k&n as good as eachother to my knowledge. I have a bmc filter, Have the same bike bought her new 90000k's and 9 yrs later been a awesome bike has been cared for very well, oil changes 3000 k's cant say a bad word about the 9 except in the snowys, high country she tends to run rough especially when cold!! icing up only drama, oh had to put a new battery in her 6mths ago what a bike gotta to love the 9's hope you sort it out good luck...

[MadKaw]

Take the mesh out of the std filter for better flow.

The only after market that flows better is a BMC race, but I wouldn't recommend it for the street.

[maraach]

Thanks for the input guys, much appreciated.

Sorry for my ignorance but im trying to work out your comment MadKaw. Would you recommend then that i do something with the filter to increase air flow considering the mods i mentioned, or should i just leave her as standard? Also just out of curiosity why do you not recommend the BMC filter for the road?

[MadKaw]

BMC make 2 type of filters, the std and the race.
The race has a thinner filter element and flows better but is not really suitable for the road.
The std BMC and the K&N don't really flow much better than the std Kawi filter but they will last longer.
To get a little more air flow, you can remove the mesh on the std filter.

Was the bike rejetted on dyno.?
If not, how were the jet sizes selected.?

[maraach]

That makes sense. Modifying the standard filter seems to be the way to go then.

The bike was not rejetted on dyno. I believe that the mechanic just selected the same jet sizes that he had used in his 9 as a basis for rejetting it. I was planning on getting it dyno'd in the near future, just thought that if i need to change the filter in the airbox before getting it done as it would affect the dyno results?

[Phil]

I'd think long and hard about removing the mesh, it was the only thing stopping mine Filter that is) going into the carbs

[MadKaw]

???

The plastic snap together frame is what stops it going into the carbs...

[Phil]

???

The plastic snap together frame is what stops it going into the carbs...

Not when its the original one from the factory thats 12 years old and breaking into little bits Ask Jamie, he'll vouch for it

[MadKaw]

???

The plastic snap together frame is what stops it going into the carbs...

Not when its the original one from the factory thats 12 years old and breaking into little bits Ask Jamie, he'll vouch for it

ah yes possibly...

Time to replace me thinks, althought the extra flow from it disintergration may explain the increase in power at the last dyno day..

I ran mine for 3 years without it, no probs, but I did have a good filter..

on side note,
when I had my zx7r (similar filter set up) on the dyno many years ago they did back to back runs with stock filter, stock filter mesh removed and a K&N (I just bought for $150) and the best resullt was the std filter with mesh removed. The K&N sat on the shelf and the std filter with no mesh was in it for the next 5 years...

[Saki]

i run a BMC in my Z1000, which is similar motor to the ZX9 and i noticed straight away the motor rev'ed up heaps quicker

[maraach]

Looks like a bit of a mixed bag of results.. guess the best thing to do would be to have a bit of a play around and see what works out best