Misfire XJ750 1981

I have a very bad misfire when riding my bike. I have checked the timing which is spot on. I have checked my carbs for sycr and set with colortuner. Bike starts on the button and idles like a dream, when i rev it there is no misfire but when i ride it it misfires very badly from first gear to fifth gear. I cant even get 100 kmh , 60 mph I am at wits end please help.

 

What do you mean by misfire? It stumbles? Won't pull (rev up) under load? Falls on its face when you crack the throttle? More detail would help here ....

 

Falls on its face when I crank the trottle

 

And wont rev up under load

 

How are the plugs? No broken wires? Good spark? Seems like it might be a spark issue, and thats definately one of the easier ones to check. What kind of bike? Year? Engine size? You should update your signature in your profile information to include that info on your bike for later reference for the rest of us =)

 

I have replaced the plugs with new ones there are no broken wires. My bike is a Yamaha XJ750 1981 Model

 

Seca or maxim? I dont think it matters much, but what color are your plugs? Black? tan? white? an extremely over-rich condition could cause that i think...

 

My bike is a seca My color of my plugs are tan

 

I would be double-checking your spark system ... also have you checked your battery? good voltage? messed up charging system can cause weird issues.

 

Ok I will go through my whole ignition system and checke my battery voltage and see if it charging properly. Thanks for your help

 

I've heard the ... what is it ... TCI? can cause issues if its going bad... not sure if that would be related to your problems or not, but i'd be double checking your coils and spark plug wires, ohm them out with a multimeter and make sure they're within spec. plug wires can sometimes have breaks in them you can't see or feel from the outside.