I have a 91cbr with 33,000 miles on it. My bike is only getting about 39 miles per gallon highway at the momment. I also dont have consistant power. it is due for a valve adjustment but wasnt sure if anything elsei should look at ... coils are good tested... didnt know if there was any chance timing chain maybe?

 

Sync the carbs. I build a carb sync tool for around $40. I have yet to test it. I am rejetting the carbs. I get about 35 miles a gallon right now. Carbs are mostly synced but i have no fairings and it seems to run rich. I do now know the quality or if the jets currently installed are correct, hence the replacement. Its only $40 for the jets (which I have) and a couple hours work. We'll see what happens when I am finished.

 

i've done it already i have the carbtune 2 so it was good

 

39 doesnt seem too bad...Try running some seafoam in the gas tank to clean the carbs and carbon deposits from the valves and piston heads.

 

Thats pretty close to expected fuel mileage. I'd go ahead and just pull the carbs and clean each jet individually. Search the HowTo forum for a carb cleaning howto for some help. If you plan on adjusting the valves I'd go ahead with that, it won't hurt anything if done right.

Good Luck!