Hello i have a 1989 honda cbr 600 It runs good but sometimes when i come to a stop sign or light the bike dies, or it sounds like it runs off couple clyinder taking off and it comes out of it like it girggles. It just started to do that maybe 2 weeks ago. I Run 93 or sometimes 92 octane i changed the plugs last week. Just wondering what it might be. I Already put over 3,000 miles on it in a couple months i drive it mostly everyday..

 

Did you change the plugs because of this or did the problem show up after you changed them?

KongBastard

 

How does it start up? Does it run like this if you start it up and let it idle, or only after you are out riding? What color were the old spark plugs when you put in the new ones? Did the bike sit for a a while or did it just run great then run bad the next day? Most of the time these problems are carb related.

 

I changed the plugs to see if that was the problem and it wasnt it only does it maybe once or twice if im driving it that day sometimes it doesnt do it.. i put NGK in it what they call for it starts ok and idles fine.. I havent changed the air filter since i owned the bike.. I Cleaned the carbs when i got the bike changed plugs oil fuel filter. but like i said i been driving it for about 3,000 miles running fine and it just starting to do it but every once in awhile not all the time.. Also its my 2nd set of plugs cause i thought that was it..

 

The fact that it runs fine most of the time makes me think that perhaps your carbs are just slightly out of tune. Is there a jet kit installed? Try to keep tabs on how hot the temperature is outside. A hot day can make you run rich. Cold day lean. So if you are already running rich in your slow jets and it is very hot, it may be enough to make the bike stall at idle.

Just a side note, unless you have some serious miles on your engine and have a problem with how it runs, (or have the heads shaved, changing your compression) you should be running 89 octane.

 

when was the last time the carbs were cleaned? maybe there is a float sticking on occasion and it is flooding at idle?

 

The bike is completely stock accept for a V&H slip on. Carbs were cleaned 3,000 miles ago. The bike has 17,xxx on it. so what fuel should i run 89? i took it to the track tonite and rode it all today it was cool out tho and didnt have a problem with the bike.. How do i adjust the carbs? what screw and what should it be out how many turns? Thanks

 

I think you need a new air filter. And I think you might need your carbs Synched. You can do it your self but you need a special tool to do it.

The second symptom sounds like bogging. Afew things can do that including vapour lock. Mine likes to bog when the engines getting really hot in stop and go traffic. When you replace your air filter I'd also check the cooliant in the rad. Might be prety old and gooped up by now.

 

Like suggested, If you cleaned your carbs, especially your float needles and pilot jets, get yourself an air filter and try to sync your carbs, you should notice a difference.

Beyond that, your pilot screws (located at the bottom of your carbs and require a screw driver tool with a "D" shaped head) may need adjusted. Are you sure your bike isn't jetted? If you bought it used, there is a good chance it is, because it is a common upgrade. The way to tell is from your jet needles, They will have multiple slots on them for making adjustments, where stock needles only have 1 possible clip position.

If your carbs ARE stock, you can hope that no one messed with anything and they are already tuned the way they should be, in that case, you just need to clean things up with the air filter, carbs and sync her up.