Topic: Carb sync - how long to the next one?

[gregk]

After going to the trouble of piecing together a vacuum guage setup, with help from the forum, I am totally pleased with the results.  I tried to justify the cost of the guages etc by saying that I have three Honda fours and I could use it on them all. ( four actually if you count the Goldwing).  The carbs on the SOHC bikes had never been balanced I think.  The yellow paint was still intact on the adjusters. 
After going through the carbs, the bikes all run smoothly at a idle with no clutch rattle.  I am ashamed that it took me this long. 
I now wonder how long until they require balancing again.  The service books and manuals idicate that the carbs should be "adjusted" every 3 to 5 thousand miles.  When these bikes were leaving the factory, the motors wouldn't have seated and I assume that there would be compression loss until the rings and valves were run in. 
Now that these bikes have a few miles on them and we must assume that all parts are run in, the interval between carb balance should be longer?

Greg

[Johnie]

Greg...I think you will get varying answers here.  If you are a finicky sort, you may do it every year.  Many feel if it runs great...don't worry about it and enjoy it.  On my KO it is sort of a pain to do with the 4 carb cable system, so I think if it runs great I will not worry about it.  However, I did mine last fall and have since added the HM300's, so I may just give it a quick look-see sometime soon.  However, if you like to tinker with those new gauges have at it. 

[Gordon]

Typically if you haven't done any work on the carbs that would mess with the slides then they don't need to be re-synchronized.  I'm the tinkering type so I hook the mercury sticks up to my 750 about twice a year only to see that they don't need any adjustment.  It's gone about four years and a lot of miles without needing to be re-synched. 

[mystic_1]

Ha ha, this is a trick question!


Carb balance should be CHECKED at tune up time.

Carb balance should be ADJUSTED whenever it is found to be incorrect.



cheers
mystic_1

[TwoTired]

Ha ha, this is a trick question!


Carb balance should be CHECKED at tune up time.

Carb balance should be ADJUSTED whenever it is found to be incorrect.



cheers
mystic_1

BINGO!

[jmckinne]

I'm sort of wondering this myself. I synced mine back in March and they are still running much smoother than before, but you can always get better

I sometimes worry about the adjuster nuts shifting tho, even tho they a double nuts. The way the throttle bar wishbones and adjuster nuts ride against each other... make me wonder.

On a related note: Tap your carbs. I bought a Motion Pro meter and after going thru the whole sync process twice last year I made an easy move in the off season. I bought a set of four 5mm vacuum fittings from Dennis Kirk and put them in my carbs where the vacuum port screws normally go. No more unscrewing those and screwing in the Motion Pro taps to do a sync. I just leave the fittings in all the time with rubber vacuum covers - just like any modern (well as modern as carbs can be these days) carb would have. It makes the whole process SO much easier. Just lift the tank, hook up the four lines from the manometer, do the sync and unhook. Makes it a 10 minute deal. Highly recommended, makes doign more frequent syncs seem much less daunting.

Lose the vacuum port screws, you won't miss them.

[bryanj]

OK, If you did EVERYTHING else first and got it 100% right before adjusting the carbs you will rarely adjust them again as long as you get all the other stuff 100% right again.

Which is why when doing them full time NO mechanic i know would adjust carbs only as a job no matter how insistent the owner was that every other service item had been done "right"