Here is the initial posting from the zx14ninja.com forum by cntrhubzx-14 (known here as Hub) made on 10/10/2007.
Figure I start a thread with all the mileage adding up on the throttle linkage, it might be time to go thru a few basic steps. Diss is the more serious part and the data needed. I have a video to cut and goof on the Lin-e-ears, and the vid is more showing you were the low speed screws are and the center shaft adjust screw.
Basically, you have 2 throttle body shafts that need a sync check every so often. The constant load on the linkage is about to go from center to firing off 2 opposed cylinder banks, if you will. That is your chain snapping when the next timed cylinder is on the other main shaft is your out of sync chain whip is the annoying clutch bang at idle.
What I'd like to do here is kill 2 birds. One is for the standard throttle body sync where you only need to touch the center main plate screw adjust. You do not or ever need to move the low speed screws. These are set at the factor like the sensors. People still think they need to mess with them but only really need to be tampered at all is if a passage is clogged and it needs to be cleaned. These are air screws and there is no fuel going thru these channels. Only dirt from the air cleaner can butt up against the screw taper and air hole which will close off the air and there is your poor idle trying to sync an open hole as opposed to a partial closed hole.
You will not start any controversy here, magee, when I tell you that the intake sensor I twist and diss the lin-e-ears with, and the sub sensors that has a ring tone if dropped (which the book says to never drop a sensor), is all about your fear factor and the code book explaining how safe the backup is to each sensor = ECU says, "I have you covered. Ride the bike without a Pcom. You do not need it is the preset."
If you decide to attempt a sync as your service interval or just to look to see where the sync plates settle out, you will need to purchase or make a manometer. Search it. This is a simple; remove 1 and 4 sync rubber plugs and watch the mercury show a level mark between each other. There is no need to know the technical numbers of the required vacuum readings, you simply move the screw so both merc tubes are even across the board. Do not move the brass air screws. Move only the main plate screw found in the center of the t-body.
Now for closed course tuning: If you remove the emissions for close course performance, you might want to re-blend the air screws to the newer tune of the a/c, pipe configuration. I doubt you need to move any air screw with the mods, but we are after the lin-e-ears who do not have a clue as to how they have their tune against your tune?
Book says to sync the mains and then blend the low screws. I will attempt the opposite set is my test first before I accept to the book sync set. You might want to stop frame so you can have a better view of the t-body in all it's angles. Be familiar with the t-body on the bike and where screws are located? The emission tubes use 3 and 4 cylinders. If you had the code-think, you could eliminate the intake vacuum sensor, plumb 4 emission fumes using this tube and you have (cannot create or destroy) vapor added to the mix is the fuel cheat, (rich mix). Use the same 4 lines to water inject or laughing gas it up with a shot thru the air ports in the t-body. You have a few combinations you can juggle with is my take on the water injection this time around, (for me that is).
As you tune for the closed course, you now close off the emission sync tubes and only use them for your air screw blends, then use either 3 or 4 sync tube to sync the main shafts of 1 and 2 cylinders. You need to have the bike hot so the air and fuel are in their running temp is the blend screw matched to the other as if you were syncing the main shafts. Blip the throttle each time to settle-out the screw settings. You need a very accurate rpm meter which KHI sells. Diss is where your ear or the manometer is the loophole to the backyard mechanic trying to work the sync another way. The bike's tach is not accurate for this work.
If you do not check compression very first thing = You will chase your tail trying to sync a low compression cylinder against a higher, healthier cylinder. They work against each other.
Diss-claim'r hanging out is the warning sign> Tuning your air screws to a; lean it too much and well, I told you so!
Note: With the throttle body in hand and tube inspections, I found the tubes to be clogged. I ran a reamer thru sync holes and found when they pressed the brass tube into the t-body, there was a piece of aluminum lodged at the bottom of the tube hole. I took a pick and cleaned that speck of aluminum that would have entered the engine (possibly). If you have the t-body off, inspect these holes for any chips that were pressed against the brass fitting and body.
* Last updated by: bgordon on 2/18/2009 @ 7:17 AM *