How to Sync Throttle Bodies on the FZ6R

[Fastprof]

I just completed my 1000 klm initial service on my 09 FZ6R and thought others might like the run down on sync'ing their throttle bodies. If you are handy with basic maintenance, you should not have problems performing this service yourself. First, you will need a sync gauge. There are many varieties of these gauges available so follow the instructions included with the gauge. I am using an older mercury gauge, but the basic principles are the same. If you have never performed this task before, it is good to have someone show you the ropes for the first time. If you already know the ropes this post will be a quick familiarization to the FZ6R's set up. Yamaha has made this much easier for us than in past models (Kudos to the engineers).

Tip: The instructions for sync'ing throttle bodies from the 07 FZ6 manual (available if you search this site) are very similar to our FZ6Rs. Note: I just finished changing the oil, so my pictures show the left side faring removed. You do not have to remove the left side faring to adjust the idle and sync the throttle bodies.

First, you need to remove the passenger seat, and then remove the driver's seat:



Next you have to remove the two panels on either side of the tank. The front of each panel has a quick disconnect fastener. You have to reach up under the faring and push the centre plunger up to release the fastener. The rear of each panel has a hex bolt. After you have the fasteners out, then carefully lift the back of the panel and pull back. The tongues at the front of each panel may require some careful angling to get them out without breaking.



Here is the quick release fastener with the centre plunger up so it can be released


Now that you have these panels off, remove the two hex bolts at the front of the gas tank


Once these bolts are removed the whole front of the tank can be lifted up. Now support the front of the tank securely with a piece of wood (aprox 16" long) or something similar that will not scratch your paint.



A good idea is to place a large fan that will blow air directly at the radiator to help cool your bike as we make adjustments. If the engine starts to overheat, you should shut the engine down to allow it to cool. Most of the adjustments are quick to do, so this really shouldn't happen.



Once you are sure your tank is secure, and your fan is on, you can now get at the idle adjustment on the left side of the bike just below the air box.


Start the bike and allow it to warm up (64 -74 degrees C should do it). You will hear the idle level off at its lowest point when it is warmed up. Now you can adjust the idle screw shown in the diagram above (Yamaha Service Manual, 2009) to adjust the idle between 1250 - 1350 rpms. -Updated July6/2010 to reflect idle adjustment correction. My thanks to Butcher Bird who caught this error

I have mine set so the tach needle is just below the first mark after 1000 rpm. Once you have the idle set then you need to hold the idle screw steady with the allen key while tightening the lock nut. Once you are satisfied then turn off the bike and you are ready to hook up your sync gauge.

See next post

[Fastprof]

Now let's look at the layout of the controls that we will use to sync the throttle bodies. Here is the adjusting block just behind the throttle bodies. Turning these screws will increase or decrease the vacuum of each throttle body



Yamaha has made it easy to attach your sync gauges by having these plugged lines already installed and ready to go. No chewed up knuckles doing this job.



Notice the line with the pink band on the left side is for number one cylinder and the same line with the band on the right side is for number four cylinder



Remove the plugs from the ends of these vacuum lines (don't lose them as they have to go back once we are done). Following your gauge's instructions connect the 1,2,3,4 lines to the same numbered lines going to the throttle bodies. The old brass adapters that came with my mercury gauges did not fit, so I found a few male to male adapters lying around my garage that worked nicely. If you do not have the proper fittings then you are going to have to run off to an auto parts store to see if they have the correct connectors.



Now that your sync gauges are connected, start the bike and let it idle. The gauge should now tell you where each cylinder is running in relation to the other cylinders. The idea is to use #1 cylinder as your reference and bring each of the other cylinders up or down to match.



In the above pic you can see that #2 and #4 are a bit too low, but #1 and #3 are in sync. Using a small flat screw driver adjust each throttle body to match the #1 cylinder.



After you have done this, gently give a couple of blips of the throttle (careful with mercury gauges as you will suck mercury into your engine if you are too vigorous with the throttle). You now may notice that the cylinders no longer match each other. Readjust again, and give a couple of blips on the throttle. You should only have to do this a few times and the gauge should show the throttle bodies are in sync. It is not necessary to have each cylinder perfectly matched, but close as you can without overheating your engine is your goal (now is a good time to check the temp. gauge on the bike).

Once you are satisfied that the throttle bodies are in sync, then turn off the bike, disconnect your sync gauge, and put the plugs back into each vacuum line from whence they came. Failure to put these plugs back in will result in a vacuum leak that will make your bike run like crap. Careful as you lower the tank back into position, make sure none of the lines are kinked or jammed up anywhere. Button down the tank with the hex bolts, and replace the side panels on either side of the tank. Careful again not to break off any of the tongues on the front of each panel. Note the unusual angle of the screws for these panels.



It took me a bit of turning and cursing before I found the right angle and the hex nut torqued down. Now simply put the quick connector in each front hole and then press down on the centre plunger to lock it in place. Now is a good time to pull down the drainage hoses on the right side of the bike and make sure they are running through the proper retainer. Also check to ensure they are not kinked.



Remount the seats, do a final check of your work. Start your engine, and
note how nicely your R is idling. Time to suit up and go for a ride. I hope this How To has been helpful.

[99vengeur]

THIS is an AWESOME how-to write-up!!! Great job!

Take note people, this is how it should be done. Text, illustrative pictures with captions, hints, tips and caveats.

[cbzdel]

Wow impressive!

[blaxx]

A very impressive write-up! When I heard about syncing the TB's I envisioned it bieng a difficult task, but now I know its quite easy with the proper gauge set.

Thank you for this valuble info!

[Roaddawg]

Agreed! Great write-up, just how they should be illustrated. I wasn't even thinking of doing this at first, but now, with this write-up, I would feel comfortable doing it. Thanks. BTW, how often is this procedure needed? Is it a routine maintainance step or just a good idea?

[xplodnstar]

Great write-up!!!

One note on the plastic rivets, though. If you push down on the center, they release easier and they will be useful longer. Pushing from the bottom wears them out faster. Do push from the bottom once they are out of the hole so they go back in and lock.

[Fastprof]

Originally Posted by Roaddawg

BTW, how often is this procedure needed? Is it a routine maintainance step or just a good idea?

Thanks for the positive feedback all. Roaddawg, the owner's manual states that the throttle bodies should be sync'd every 7000 klm. I do this once a season, but may sync them again mid season if the idle seems rough.

Xplodnstar, thanks for the tip on the quick release fasteners. I learn something new every day.

Great pics and coverage! BTW - Not always easy to find enough stepped vac addaptors that join the small yamaha vac hoses to larger manometer hoses in stock. When adaptor shopping try looking at brass fuel line connectors for nylon fuel line - they don't have as big a barb as plastic vac line conectors so are easier to take apart when finished. My 2c.

[cbzdel]

where do you get a sync gauge like that??