Motorcycle Repair: Nighthawk Carbs, honda nighthawk 650, poor fuel economy

Question
Mark,

I have an '83 Honda Nighthawk 650.  If i am not mistaken my carbs are getting a little out of whack.  I have noticed that my gas mileage is diminishing.  I myself have had the bike for about 3 yrs.  The first year i was getting about 120 miles out of a tank now I am down to about 75.  Every so often when i start it up now I still get the blue smoke coming out of the pipes.  It does not idle real well until i run it for a few miles.  I am wondering if this is a matter of just cleaning them or do they have to be replaced or what?  I am somwhat mechanincally inclined (with cars and not bikes) so is this something I could do myself?  If not, do you have a ballpark estimate of what that would cost to have done?  A friend of mine who has an R6 just had his carbs cleaned and rebuilt and got about 22 more hp out of the engine.  I know this is a lot of info but can you help me out at all?

Troy Urban
theoaf66@yahoo.com

or

troyurban@emaillcu.com

Answer
Hi Troy,

If the carbs are in good condition and synchronized fairly close, usual cause of excessive gas consumption is worn needle jets. They wear oval shape from the jet needles rubbing against them. This causes poor fuel economy and changes the amout of fuel metered past the needles.

Check your email for repair and tuning files.

Respectfully,
Mark Shively