Topic: 79 cb650carb sync

[Thor0812]

I have a 79 cb650 i recently pulled and cleaned carbs, jets etc. Put them back on and got everything adjusted and the bike runs pretty good. It is a hair slow to return to idle and there is a slight tick. I am pretty sure the carbs are out of sync a little but I dont have the cash for a sync tool or to get them done. My question is, will it hurt the bike to run it this way for a while till i can get the gauges? or will it be better to wait?

[Thor0812]

Anybody have any input?

[CBJoe]

I think that depends on how out of sync they are.

I'd do the plug check comparison to see how evenly all 4 plugs match up. Hopefully someone will chime in with a better explanation on what the negatives are of running out of sync.

Regards...Joe 

[eurban]

One thing that helps and costs you nothing (other than time) is to bench synchronize your carbs before you install them back on the bike (after a carb rebuild).  This means that you adjust all the slides to be open the exact same amount a given throttle setting.  #2 slide doesn't adjust at the upper linkage so it is your baseline.  Turn the throttle knob until a convenient object like the back end of a 1/8" drill bit just fits between the bottom of the slide and the carb bore.  Now adjust all the other slides at the upper linkage until they are open the exact same amount.  Assuming that your engine is functioning OK, this will get you pretty close.  A proper gauge synch will smooth things out but you should be OK for a while with just the bench synch.  Ticking isn't typically related to synch issues unless you are refering to the bucket of marbles sound in the lower crankcase/clutch area that is typically diminished by a good synching.  "Ticking" is more likely a valve clearance adjustment issue or a top end problem. .  . .

[Thor0812]

Thanks guys. Speaking of the valve clearance, how the heck do you get the feeler gauges in there? Is there a special tool you guys make to do this? Every couple of days I try but still cant get in there. I have checked the plugs and they all look the same, nice and clean. Like I said they are pretty close but just not perfect

[martino1972]

i got a set of feeler gauges that is pretty narrow at the tip,and i just bend the tip to get the right angle..