Ok so first off i have a 98 cbr900rr with 18xxx miles has shorty yoshi pipe and jet kit when i first got it about a month ago it ran fine i had no problem giving it full throttle in any gear and she would take off no sputters no nothing ran great .

Last week I was on I75 at 2am , no cars just me and wide open road so from 6th i drop it down two gears and open up the throttle and i go nowear i looked at my RPM's and at 5k it just sits there sputtering and jumping like it wants to go but is choking. so i roll off throttle and then it stops sputtering. so to make a long stopry short whenever i use WOT the bike sputters in all gears but if i use 3/4 throttle its fine and no sputter.

I changed spark plugs to ngk plugs

I changed air filter to another paper one but brand new (didnt have enough money for K&N)

I added seafoam to gas tank and carbs and i have been thru 2 tanks so i dont believe its bad gas

I was told the carbs where cleaned 2 weeks prior to me buying the bike ( remember bike ran fine when i bought it for first 2 weeks or so)

I noticed a small hole in one of the intake manifolds ( rubber boots from air box to carbs) when i was putting seafoam directly in carbs i noticed it came out side of boot. so i ordered a new set.

also there wasnt a gasket in the airbox when i took out the old one.

My main problem is what could have changed i didnt do any services or tinker with anything mechanicle till after this problem started to occur

since changing the plugs and air filter it doesnt sputter as much except for the higher gears 4th 5th 6th its like a govenor chip in a car win i use full throttle it just starts to sputter and bog and not go anywear =(

Please someone with some helpful information please help
Thanks guys!!!

 

Main jets & emulsion tubes clean.. Ran good for 2 wks.. U changed plugs & intake boots.. Tps bad, i would think across the whole rev range.. What about the pre charge filter under airbox.. Might have dried up and sucked into carb dia. Not letting slude move as should.. Happened 2 my 99 when i 1st got it??

 

I havnt changed boots yet i plan on it tomorrow tho

Tonight i was looking in my gas tank and noticed some things floating around and that worried me so i emptied out all the gas in my tank into a bucket.....OMG the amount of crud i found in my gas tank...(it actually made me mad) so i am wondering....maybe all this junk was clogging the filter in the tank when it was trying to suck gas and it was LITERALLY GASPING FOR GAS!!!
Sorry for massive picture i need to learn how to resize =) lol

and as far as the pre charge filter...is that the filter in the tiny little box thing under/behind the airbox because i was looknig at that the other day and notice there wasnt a filter in there and i dont know if there ever was or not....but if it did get sucked up into carbs.....would my bike hardly run???

THANK YOU anyways for info

 

Yeah, there is supposed to be a filter there for sure. It is very possible it disintegrated over the years and possibly got suck in over time. Gas would break it down even more so it wouldnt just kill your engine, just make it rough. From what Ive seen in past 900's is that people pull that apart, see that its getting old and just throw it out and not replace it. If I were you I'd pull the carbs, do a full cleaning (Or find a good shop that will do it for you depending on know-how and $$) That way there is no question about clean carbs, jet sizes, etc

Good luck, and Replace that pre-filter