Join Date: Jun 2002
Location: West Palm Beach, FL
HELP! Sync Carbs for 99 CBR F4
My neighbor and I tried to sync the carbs on my 99 F4 last night. We had to end up removing the airbox and fuel tank just to get to the adjustment screws. What a pain in the A$$!!
Anyway, the service manual from honda is of no help as it just mentions that the #4 carb is the base and that the pressure for each should be 30mm of mercury or 1.2 Hg (I can't remember off hand, but I believe those numbers are correct.)
We proceeded to sync 1 to 2, then 3 to 4, then using the middle screw adjust the 1-2 bank to the 3-4 bank. We couldn't get the #2 carb to come up, and finally figured out that one of the fittings for his pressure gauge was leaking aparently leaking. After this we tried to sync 1 to 4, 2 to 4, and 3 to 4 by only hooking up the good pressure guage fitting one by one to the 1,2, and 3 carbs. Now the whole thing is F'd. First, it sounds off. Second, when you blip the throttle, it takes a longer now to settle back down to idle.
We are going to try to buy another pressure guage. Until then, any ideas or help would be greatly appreciated since we don't have any real instructions on how you are supposed to do this for a '99 CBR600.