[nof900RR]

Heloo every body Q: I have 96-CBR 900RR with yoshimura RS-3 bolt on , 28 in jets .Im running lean , needles are in the right setting , should I go with bigger jets & how big?????? Thank you

[bladeracer]

Originally Posted by nof900RR

Heloo every body Q: I have 96-CBR 900RR with yoshimura RS-3 bolt on , 28 in jets .Im running line , needles are in the right setting , should I go with bigger jets & how big?????? Thank you

Is the bike running lean?

[nof900RR]

yes sorry for mis speling it , yes lean

[nof900RR]

sorry for the spelling ,but yes lean

[bladeracer]

Originally Posted by nof900RR

yes sorry for mis speling it , yes lean

I figured it was a mistake but I read it as running fine rather than lean :-)
What do you mean about the needles being at the right setting?
Just like jet sizes, the right needle setting is wherever it needs to be so as not to run lean.
You need to determine which part of the rev range is lean.
And what does the "28 in jets" mean?

[nof900RR]

The size jets are 26 in the mid &28 on the outer carbs

[bladeracer]

Originally Posted by nof900RR

The size jets are 26 in the mid &28 on the outer carbs

I don't have an earlier manual than but '96 lists:
Mains are #115.
Slows are #40.
Needles outers are J5FB and inners are J5FA.
Pilot screws 3 turns out.
Float heights 13.7mm.
The needles don't appear to be adjustable so you probably have aftermarket needles?

The '95 fiche lists: 1995 Honda Motorcycle Parts for CBR900RR, OEM and Aftermarket at BikeBandit.com
Mains are #115.
Slows are #40.
Slow air jets are #115.
The needles aren't specified.
It appears to run different mains and needles in the inner two carbs but they aren't specified.

So the first thing we need to know is are the carbs stock or have they been kitted?
Which jets are you saying are 26 and 28?
Are the needles adjustable.

Then, before actually changing anything we need to know if the bike was fine before and this is merely a result of wear. How old are the air filter and spark plugs?

[nof900RR]

Sorry for lack of info
the jet size 128-126 , yes its been kitted , The bike was basket case & I build it myself & it ran ok... in the lean side so I went up with the jets to 128 ,it got better but lean , so should I go up to 130 & whats that going to do do to my gas mileage ( its a Daley bike ),filter K&m good shape ,all most new top end , new sprk, every thing , my pips are yoshimura RS-3 bolt on What size jets & needles recommended for that pipe on 900rr ???? To know that will point me in the right direction I think..... thank you

The needles are adjustable & thy are one steep under the highest adjustment & yes I went to the highest & it got rich

[bladeracer]

Originally Posted by nof900RR

Sorry for lack of info
the jet size 128-126 , yes its been kitted , The bike was basket case & I build it myself & it ran ok... in the lean side so I went up with the jets to 128 ,it got better but lean , so should I go up to 130 & whats that going to do do to my gas mileage ( its a Daley bike ),filter K&m good shape ,all most new top end , new sprk, every thing , my pips are yoshimura RS-3 bolt on What size jets & needles recommended for that pipe on 900rr ???? To know that will point me in the right direction I think..... thank you

The needles are adjustable & they are one steep under the highest adjustment & yes I went to the highest & it got rich

I would recommend swapping the filter back to an OEM one or a BMC.
What brand of jet kit is it?
Where is it lean - top end, idle or transitioning from cruise to full throttle?
Does it start fine without throttle when hot but require choke when cold?
Fuel economy is irrelevant. If the bike is running leaner than you like and you want to richen it up then it'll burn more fuel - not much you can do about it.
What does "highest adjustment" mean on the needle - highest position for the clip or the needle?
How are you determining if it's lean or rich?