Hello,
I'm a fairly newCBR member and amignorant as far as engine problems. My question is this: when I let my 98' CBR sit running and watch myRPM guage idle, I notice my RPMs are inconsistent (jump around) a bit. Not extreme contrasts but it jumps around in a gap of about 500 RPM. I know this isn't a lot but it isn't stable like I think it should be.
I don't think it should be jumping around in RPMs...or is this normal on F3s? I ordered a service manual recently and I should get it via snail mail early this week. Before then, have you ever experienced this? Is there anything I can check and do myself? I appreciate any useful input.
Thanks in advance

 

You can download the manual, while you wait for the snail to show up. Best i can do

http://www.stephygee.com/F3manual.zip

 

well if the bike is not warmed up it will idle low then when heated up the idle will rise a little .set the idle when the bike is warmed up

 

It might not sit right because of how the air and gas get to the engine. It's not as pin-pointed as a car is or as a fuel-injected bike. It should be fine. As long as it's running strong. don't worry about it.

 

LlanoSV,
That does actually make sense since it's ran through a carb. opposed to fuel injection. I guess that is to be expected. It does run strong.
Also, my manual came today so I will see what they have to say about it.
Thanks

 

The engine when warm should be set to idle at 1400 rpm +-100 for California models (fitted with the EVAP) or for other UK and US models it should 1200 rpm +- 100. It should run a little jumpy but if its too much your carbs may need balancing. This is felt by a vibration thru the bike when its bad. Or they may need a clean. Hope this helps.