ok lemme start off by saying the problems/symptoms.

1. idles a little rough ,kinda choppy throttle from idle to 2k rpm after that its ok
2.kinda back fires every so often not loud or alot.
3.sounds like a little misfire from bad gas or dirty carbs.
4.Bike was stored for 2 years before i bought it i thought carbs and tank had bad gas and varnished inside of carbs.
5.once bike got over 2.5-12k rpm's the bike ran out standing.
6.once at speed like lets say 30mps 2nd gear at 2.5-3k rpm if i were to throttle hard it would hesitate and then take off.

Ok with most of the problems out there this is what a friend of mine did.

1. Taken off carbs and inspected extremely clean someone had it off and cleaned before he did.
2. Happen to notice the intake valves had varnish on cylinder 2 and 4 real bad.
3. inspected cylinder 1 and 2 perfectly clean.
4.his thoughts were thats why the hesitation was the build up on the intake valves not the carbs.

Our plan of attack- 1. calling local garages to see whats best.
2. Inspected his ninja and found his were clean all 4 cylinders
3.possibly taking head off and removing valves cleaning and lapping valves and reinstalling.
4. Asking the PRO'S on CBRFORUMS.COM

Anyone here have any knowledge of what to actually do or ver seen this, or even has thoughts what could have cause this and how to fix it the best way.

Thank you for reading all imput is greatly appreciated.

 

maybe try bigger idle jets
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What do the plugs look like? They may be unserviceable or incorrect for use in the 900RR motor. According to Honda, the only two listings for approved plugs in standard heat range are:

NGK CR9EH-9

Denso U27FER

 

Even if you replace all the filters and clean out the carbs and gas tank... run some SeaFoam brand engine cleaner thru your gas tank. Go by the directions on the can. It does work. I saw my valves before i used the seafoam and then after.. 50-70% cleaner after. SeaFoam also works as a fuel stabalizer for winter storage. Most autoparts stores sell it.

My bike runs like crap below 2,000 rpm's when it's cold. In fact it BARELY runs at all below 2,000 when it's cold. My guess is you have some junk built up inside the idle circuits of your carbs. Those are the tiny tiny passages that allow fuel to flow while the engine is idling and at low rpm. I ran a thin piece of copper wire strand up thru those passages then blew compressed air thru them. This was all done with the carbs taken apart and off the bike. It could very well be spark plugs being fouled. Good way to tell is buy a new set.. if it runs great for a day or two then starts running like crap again, you have a problem. My bike fouls plugs like crazy. I believe the problem with my bike is a leaking head gasket or worn valve guides allowing oil to get into the combustion chamber, thus fouling the plug/s. The only other thing that i can think it could be is leaking o-rings on the fuel enrichment circuits ( choke).... thereby always letting some fuel to leak into the combustion chamber.. to much fuel for the spark plugs to burn off so they foul. These are just theories, but i've had a long time to think about them. Also worn piston rings can let oil into the combustion chamber... instant spark plug fouling then. spark plugs don't like oil.

Do a leak down and compression test on each cylinder. This will tell you how good/bad your piston rings are and valve guides. Valve guides when worn down can let oil into the combustion chambers.

 

heres a thought...may be wrong may be right....I bought my f2 when it wasnt running.....simple fix and it ran great for about 3-4 weeks...then I noticed that sometimes it would sound like one of the cylinders was not firing correctly because it would sound allmost like a v-twin till about 3500rpms...and was a noticble amount faster...then it was like it went back to normal and took off...it didnt do this all the time but did it enough for me to be concerned. Then about a week later it just stopped running...so I tore it apart...finding the brand new plugs to be fouled and the engine to be flooded.....I had no clue what was going on...so I cleaned the plugs..let the flooded motor sit for a couple days without the plugs in to try to get as much of the gas out as possible...then put it back together and it ran fine again..then about a week later same thing...and so this time i took apart my carbs...and they were completely filled with gas...so I drained them..and talked to the local dealer....turns out it was a "float valve" inside one of my carbs...which basically controlls the amount of gas that is being pushed into the motor depending on the throttle...well it was stuck open.......so eventually the engine would start to flood...and then it would burn off at a high enough rpm....sounds kind of like the same problem, check it out.

 

ugs are brand new i havent checked them probably have 3k miles on the, sea foam i have heard of it and never considered it thanx for that, As for the other two posts thank you for your imput ill certaintly try everything possible with zero to low budget repairs thanks.