I were out with my bike 3 days ago and after i had given som gas the bike suddenly started to sound. Hard to describe the sound but i first thought it went wrong when i downshifted. After that the sound disapeared but i could feel the power ran away. And felt that the bike didnt run on all cyliders. And I were right. Cylider 1 and 2 doesnt work. The bike only run on 3 and 4 now..
I tried to check the ignition with new spark plugs and i think it were okey.. What shall i do next?
What is wrong?
Please try to give me a tip.. English is my second language so i hope u understand me.


CBR 600F 1999, New sparkplugs
/ zigurd

 

Check your leads 1st, but may be a faulty ignition coil.

 

+1 Coil imo

 

ur english isnt too bad you got your problem across pretty well. Check your coils

 

Is the coils a common problem on cbr 600?
I took the sparkplug with ignition coil and laid it on the engine, started the engine. I could see a spark but maybe not enough. i could also see rust on the ignition coil.. on all 4.

 

Clean the rust off and see if that helps. WD-40 works great for rust removal, then use electrical contact cleaner to clean off the WD-40. If that helps, great, if not check ebay for some coils. If by "give it some gas" you mean filling the gas tank up, you could have got bad gas, or stirred up some rust in the tank clogging up the fuel line.

 

By given gas i meant "step on the gas"..
I gonna take the bike to a friend that work as a mechanic, hope he can give me a clue.

 

I have found the reason why it just fire on 2 cylinders. The pistons in the cylinder 1 and 2 has probably encountered the valves, which now does not seal becouse of that. Is it possible to fix this with a Repair Manual? I am not sure if have the skills that is needed. It is a big operation but im not sure if its 2 big.