Bike is back firing - 1998 Honda CBR 900 RR Fireblade

check coil and rectifier

are the teeth on the clutch plates good?

If you change the exhaust pipes, you have to sync the carbs (if you cant sync them, you have to change the carb jets), usually it is backfiring because the carbs are not in balance.

plugs are normally preset,not sure of your bike but sounds like you may have put plug caps on wrong plugs and firing order is now wrong. if its a 4 cyclinder bike , 1-4 fire together as does 2-3 . # 1 IS L/H SIDE OF BIKE SITTING ON IT

visit xjbikes.com there is a lot of info there .

Hi hall ie
I just replied to your last question about firing order
I couldnt get back to you with a reply to your idle screw question due to a software problem
Has the bike been unused for a long time?
Please review your last 2 questions (which I've answered) & gimme some feedback as it helps my ratings
Ride safe
Bike-Doc

Check the igniter. Go back to the dealer and ask him to see one. Then go back and find it on your bike. Yamaha's usually have them under the seat, or left side. But I don't know exactly what year you have. Run the VIN on the frame under my tips and tricks is a web site that'll break it down for you.

back fires through exhaust too rich
back fires through carb/air box too weak..
if the front cyl is falling away sound like its not getting fuel? weak..?

did you get it checked for cylinder pressure? take out spark plugs, clean them out and observe for any oil or deposits

open the airbox and clean the airfilter. If you have made any adjustments on the carb you may need to retune it as sometimes vibrations can alter them. Also if it has a file line filter check that its not clogged or obstructed in anyway.