hey everyone, my names vinny i have a 1998 cbr 900 and i need help.

a year ago i knew nothing about engine maintenance. then one stupid day in a parking lot i did a wheelie a little two slow, jammed the throttle at 12 o clock and rode that thing across a parking lot over two curbs into a fence. it didn't actually hit anything (except me) but it was running upsidown for a good 20 seconds or so,

besides all the ferrings being ripped off from the bush, there really isn't much damage. the forks were bent from hitting the curb, and both rips had warped, but the frame itself and the engine was untouched.

now, that day was fathers day last april (almost a year now)

since then i have done nothing but read diagrams build paper models of carburetors and study my *** off to understand everything that could possibly be wrong with this bike.


now the problem... it will start right up, and idle forever. it will get up to operating tempature, and sound healthy, but any throttle will flood the engine, (or at least lower the RPM substantially I'm just assuming its flooding)

now what I've done to it.....

*took out the intake manifold, was covered in oil, cleaned the whole thing out spotless.
*put new spark plugs in (they were FILTHY too)
* took the carbs off and cleaned them super well and was REALLY delicate with the vacuum chamber needles.
*bought a motion pro carb sync and synced the carbs,

now will all of this I'm seeing improvements with the engine pitch and sound, but as of now, i am at a dead end. the only step i can think i missed was directly messing with the fuel air mixture screws... (not the carb sync screws that other weird flat sided screw)

i have two videos of my bike running, one before i cleaned my carbs and one after.

i miss this bike so much and I'm willing to read anything buy anything DO anything i have to do to bring it back from the gates of hell...

please help~!!~

 

I would look for an intake leak, hose off, etc. Maybe something that got pulled or pinched when wheelie passing 12o'clock...then up side down. Another sign of a possible vacuum leak.

 

Also check the fuel flow..... From the tank, petcock, fuel filter...make sure nothing is pinch, bent....when throttle, if bike short of air or gas...will cut off...I believe there is also a throttle sensor? Make sure it's connect properly.

 

throttle sensor? where is that? because there is some damage on the very bottom of the pulsar cover, the screw got bent and broke

here is a video i took the other day after i cleaned the vacuum chambers

Post vaccuum chamber cleaning... Mild throttle response!! Prog... | Facebook

i think that should work... the thermostat is at 210 but the bike had been running for about 20 mins,

and as for the fuel source, i have a gravity fed system

 

here is another video of me pulling on the choke, and then I'm twisting the throttle a little

CBR 900rr diagnoses. HELP!!! *warmed up to 170 F - YouTube

you can see how it just drops... and when it goes up with my hand on the throttle I'm actually closing it... i had to adjust my throttle cables because of how far open i mustve twisted the grip

 

when you cleaned the carbs did you remove, touch the sensor on the left side of the carbs housing? ...IF YOU DID IT NEEDS TO BE RESET BACK TO FACTORY SETTINGS....

 

Are you talking about the idle screw?

 

No, he is talking about the throttle position sensor. Actually it is more like a butterfly position sensor. It is on the end of the carbs. Hard to miss with the wiring connected to it...