Honda CBR600F3 - carburetors problems?

[mladenpn]

Hi everyone,

My name is Mladen and i'm coming from Serbia, i hope that you guys can help me to solve problems with my bike because i can not find really good mechanic in my environment.

Last year i bought Honda CBR600F3 from 1996 and i have problems because from 4k rpm up to 6k rpm i have big lag, something happens and engine does not have proper combustion i think. I took bike to best mechanic i can find, he dissasembled them, took carburetors in ultrasonic bath, assemble it again and adjust with vacuum instruments. It was little better because lag was smaller but it was not completely solved. Another thing, when i start cold engine, idle speed is about 800rpms and when it warms up idle speed goes up to 1700rpms.

Can you give me some advices how to try to solve this?

Thanks in advance.

[Hairsy]

Hi.
 

If idle goes up when the choke comes off then it suggests that the bike is running too rich. When the choke comes off, the mixture gets leaner.

 

And if it’s running too rich then it’s unlikely to be a vacuum leak problem. 
 

Definitely sounds like a carb problem. 
 

Ultrasonic cleaning is good but jets need individual careful but thorough cleaning. Or replacing with OEM quality replacements. 

[Egon247]

Ultrasonic cleaning won't shift dried on petrol. Trust me here. I've just rebuilt my 1000FL carbs. And I have a small ultrasonic cleaner. It just laughed at the varnish.

Get the mixture checked after checking the jets and floats.

[Punts]

Make sure the air ducts are all connected properly from the front duct to the air filter cover. Leaking or poor connections can effect air fuel ratios at mid range.