I got a problem.

My 99 900rr is bogging down at low rpm's. The exhaust has gotten a lot deeper and louder. and when i decelerate it sounds like fire crackers. I cleaned the carbs kinda. ran alot of seafoam through it and cleaned the petcock real good. the problem started when i took the gastank off to paint. i thought i might have gotten some paint in the carbs but theres been like four or five tanks of gas through it since then. I hoped the problem would fix itself but its not. also when i first start the bike it runs better than a half hour down the road. any advice on the next step.

Thanx

 

sounds like a rich condition. Only way to fix this is to take your carbs off and clean them, thats the first step. Seafoam is not a cure all and if you got anything inside your fuel system when you took it all apart then its not gonna fix itself. If it ran right before you touched the tank then you should start there, cause that's the only thing that changed. Do the carb cleaning right by taking everything off and putting it in a cleaning tank or ultrasonic cleaner. If you can't do this the right way then you should turn it over to someone who can do it or else you will be chasing your tail with fixing the problem. Could be a problem with the choke too. Good luck.

 

carbs are now clean as a whistle. new KandN filter. Spark plugs look good. Still having the exact same problem. When i took the carbs off the valves (i guess thats what they are) were dirty as hell. the carbs seemed pretty clean though.

a mouse got into my airbax and built a little nest. i got a new filter but not before i rode about 100 miles with the old one. could this have done anything? And could it have something to do with my exhaust. Dumb question but is there a cat converter. and if i gets cloged could this be the problem.

im staring to get alittle frustrated. thanks for all the help.

 

how did you clean the carbs, step by step? There is no cat so thats not the problem. The bike is still running rich, you might just want to take this to a professional if your getting frustrated because you need patience and a good knowledge base to fix problems like this. Is your plug gap set? when you say your valves are dirty what are we talking about here? And in the process of taking the carbs on and off can you garnatee that you have no vacuum leaks at the boots?

 

I took the carbs off the motor. Pulled the caps and the bowls off on ecarb at a time. Pulled the needle thing out and sprayed and inspected all the nooks and crannies. I took all the jets out that unscrew and inspected and cleaned them with spray. everything was already clean. the floats were going up and down as they should with no sign of sticking. i took all the plastic caps off and sprayed all those jets too. when i pulled the carbs off, right underneath are the valves right? it looked like there were 8 of them. They all had a dirty looking oil type stuff on them. I just changed the oil so i know thats clean.

what would a lean mixture do to a bike. My friend suggested that maybe the mouse hole in the first air filter and then the increased flow of the new KandN filter could be causing a lean mixture. Is that possible?

I pulled all the plugs but didnt check the gaps. they all looked good and the same. would a petcock from a 93 600 work on my bike? are they all basically the same? thanks again for the help. im close to taking it in to a shop but i like working on it and trying to figure out stuff. its the only way to learn.

 

how do your plugs look? If they are white or really light then your leaned out. If you have dark or wet looking plugs then your rich. When you rev the engine at idle and cut the throttle abruptly do the revs hang up about the idle speed? Or do they drop below the set idle and then come back up? The stock filter and K&N are one and the same I thought. Maybe that is totally wrong but still the K&N shouldn't require re jetting. If you had a free flowing exhaust then you would have a different story. Let me know on the above questions and you might also try pulling the choke up and see what that does to the sounds and idle, you will be make the bike run more rich by slowly pulling up. Give it a try after warm up and see what happens. Good luck

 

you should be syncing the carbs too, by the way. I don't know that that will help this issue but its a must after all the work you have done.

 

I believe when i rev the engine at idle it drops down to n ormal without dipping below it and coming back up. Im not with the bike now so ill have to check for sure. the plugs looked good as gold. not oily and a kind of dirt brown color. And they all looked the same. When i pull up the choke it acts like normal, the bike idles higher. What are the chances that its an electrical issue? i was thinking about pulling the exhaust and checking to see if a mouse built some sort of rock solid structure in there. Is that a possibility? I probably will take it in to have the carbs synched but id like to figure this out first.

 

still having the problem. Heres what already been done. carbs cleaned and synched. gas tank cleaned and all vents and overflows checked for operation. Petcock checked and cleaned. Air flow checked and cleaned. All these things are good and i still have the problem of **** for power and firecrackers on deceleration. Also new plags, KandN filter and good ignition coils off a used bike. could an exhaust leak be causing this? some guy at a shop siad i could have blown out the baffel in my muffler? My girlfriend did back into it before all this started but she just knoked it over. no real apparent damage. and are you sure that a KandN filter and a slip on exhaust would not need a jet kit. please help. please, im begging you, please help.

 

yes any exhaust leak will cause popping. If you changed the exhaust and filter and this all became a problem then yes you need to re-jet. If the bike ran better before then started having issues without any modification then something has changed that you were not responsible for. You have covered all the bases and hopfully the car cleaning was done well. I for example took my carbs off last year and cleaned them very well and blew everything out with compressed air. The bike ran very well. But this year I took my carb bank to me work and used the ultrasonic cleaner, and the difference is amazing. My ike runs smoother than some of my friends FI's and the power and acceleration are perfectly linear. That why I stress the need for professional carb cleaning because no matter how thorough you are there can be a passage that has buildup that you can't get to and it will throw off the entire setup. I know ultrasonic cleaning isn't always available locally so maybe you have to ship them. However,most engine builders should have a hot tank in their shop, and that works well too. YOu have done a good job covering all the bases, I wish there was more I could tell you but without seeing how you did everything I can't really offer you anything else. It might be time to find a ship with a Dyno and then they can cheack out your A/F ratio and tell you right away how your jetting is. Good luck