Throttle Body Sync
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for GEN III it is Nr.1 and it should be marked from the factory with white paint.
dcumpian
Well-known member
^ this is true. You will find that the one with the white dot was left in the fully closed position from the factory. It was the cylinder with the lowest vacuum when all four were fully closed.
If you find that one of the other three cant be lowered enough to match that white dot reference vacuum, even when fully closed, make that one the new reference and match the other three (including the one with the dot) to it. This has happened to several people here.
If you find that one of the other three cant be lowered enough to match that white dot reference vacuum, even when fully closed, make that one the new reference and match the other three (including the one with the dot) to it. This has happened to several people here.
IF you haven't figured it out by Feb/Mar next year, I'll be in Thailand and can help get it done.
Thanks everyone for the responses. Bryan Glynn (of FJR Enthusiasts) says in his video that its number one and that this is the one that the computer is set to, so don't adjust it. I'll look for the white mark and use that one! Any more info would be welcome.
And thanks Harald, look me up when you come to Thailand and we can perhaps have a beer together. I'm in Phuket.
And thanks Harald, look me up when you come to Thailand and we can perhaps have a beer together. I'm in Phuket.
I'm spending most of my time in that area on a dive boat in the Andaman Sea and then in Khao Lak, but will have one night in Phuket on February 26th before flying to Chiang Rai. Be great to meet you if you're available.
Boston
Well-known member
I know this is 6 months old.
Nothing tells me a base setting. Like fully seated or turned out slightly. The service manual only said if the screw is removed to turn in 3/4 turn.
So the Master is fully closed? (lightly seated ) To start and remains closed?
With mine they are all reading the same fully closed. Is this ok?
Nothing tells me a base setting. Like fully seated or turned out slightly. The service manual only said if the screw is removed to turn in 3/4 turn.
So the Master is fully closed? (lightly seated ) To start and remains closed?
With mine they are all reading the same fully closed. Is this ok?
kmanflyer
Well-known member
Boston
Well-known member
is a great write up. Thank you kman
kmanflyer
Well-known member
Boston, You're Welcome, but thanks should go to Fred W and dcarver, they made it happen.
Folks reading along should be aware that the Really Definitely Completely UnAuthorized TBS procedure (which should work fine for Bostons 05) only applies to 1st and 2nd Gen FJRs. In 2013 Yamaha changed the throttle bodies significantly when they also went to Fly-By-Wire throttle control, and ECU controlled choke and idle speed.
On the earlier throttles the vacuum balance air screws needed to be open at least a little bit (3/4 turn) to supply adequate throttle plate bypass air at idle. In 2013 or later since the throttle plates are ECU controlled at idle there is no need for bypass air except to balance the cylinders vacuum to each other. They also removed the adjustable mechanical linkage between the throttle bores so no more balancing can be achieved at anything above idle speed. The linkage is fixed at whatever it is.
On a 3rd Gen, if you can achieve good vacuum balance at idle with all four screws fully closed then that is where they should be. Your bike is a unicorn. Go buy a lottery ticket.
If they are not completely synchronized you only open the screws with higher vacuum levels to bring them down to match the one that had the lowest vacuum when fully closed. Thats why the reference screw (with white dot) is always fully closed. The reason for doing this is it minimizes the air screw throttle plate bypass air, which gives the most control to the ECU for idle speed control.
Hope that helps.
On the earlier throttles the vacuum balance air screws needed to be open at least a little bit (3/4 turn) to supply adequate throttle plate bypass air at idle. In 2013 or later since the throttle plates are ECU controlled at idle there is no need for bypass air except to balance the cylinders vacuum to each other. They also removed the adjustable mechanical linkage between the throttle bores so no more balancing can be achieved at anything above idle speed. The linkage is fixed at whatever it is.
On a 3rd Gen, if you can achieve good vacuum balance at idle with all four screws fully closed then that is where they should be. Your bike is a unicorn. Go buy a lottery ticket.
If they are not completely synchronized you only open the screws with higher vacuum levels to bring them down to match the one that had the lowest vacuum when fully closed. Thats why the reference screw (with white dot) is always fully closed. The reason for doing this is it minimizes the air screw throttle plate bypass air, which gives the most control to the ECU for idle speed control.
Hope that helps.
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RossKean
Well-known member
For Gen I and Gen II, if starting from scratch I would screw all four in to LIGHTLY seated. Now, open each to something around 3/4 turn from fully closed. For most bikes, this is a pretty good starting point. The posted link in #10 is very good. (The link opens WAY better in Chrome than it does in Internet Explorer.)
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kmanflyer
Well-known member
This is true after you set the linkage connecting the throttle plates.
My interpretation of the Unauthorized TBS is setting the throttle plates so they draw equal amount of air past the throttle stops. The initial setting with the throttle lock device holding rpm and bleed screws closed is to eliminate the bleed circuit affecting the throttle plate adjustment. After the throttle plates are set than it's pretty much just a plain TBS with setting the bleed screws equally after an initial 3/4 turn out after lightly seated. Adjust idle speed to 1100 rpm after every bleed screw adjustment and throttle blip. The FSM Vacuum pressure at idling speed is 33.3 kPa/250 mm Hg/9.8 in Hg, that is just a ball park.
This is for Gen 1 & 2. Gen 3 is different as explained by Fred above.
dcarver
Well-known member
RossKean
Well-known member
Your Candybutt site almost got me into trouble at work. Seems our server filters interpreted it as porn and blocked it - probably reported it to IT. I guess it is motorcycle porn...True That!
(I don't think it liked the "butt" part of the URL!)
I just hope they don't add motorcycles to the blocked key words.
OhLuckyMan
Member
Hello fellow fjr owners,
I have just read many of the posts on this site, in my search for all the information I can get on how to do my first Throttle Body Synchronization. I am riding a 2016 Gen 4 fjr1300A.
I have a few questions, and they mostly are about the really nitty gritty little stuff that seems to be being left out. Here they are:
1. After raising the tank, to get at the throttle body nipples, I find that I cannot reach them all. Some are 5-6 inches below pipes and hoses on the surface of the motor, and very hard to reach. I'm pretty sure that I will have to remove the gas tank, then hook up the Carbtune, and then hook the gas tank back up, to get at the 4 necessary hose hook up locations. Has that been your experience?
Brian at TwoWheelObsession does a very good video on how to do a TBS, but he is working on a Gen3 2014 bike. I'm on Gen 4, and just don't see how I can do this without removing the tank to get at the necessary areas.
2. Also, I cannot find a suitable tool that will assure that I can get the little ring clips and black caps off without losing them into the abyss of the motor. Any tool suggestions?
3. The TBS adjusting screws are just forward of the rear of the gas tank, and face toward the rear of the gas tank. There is probably no more than 4-6 inches of room between the rear end of the gas tank, and the two inside TBS adjustment screws. With the engine nice and hot, as required to do a TBS properly, and the gas tank overhanging the work area, I just can not see me getting in there with out removing the tank, and having it hooked up , but out of the way. Does that sound right?
I replaced the plugs while I was under the tank, yesterday. That was the very first time I have done a spark plug change. I found it a little tricky getting the ignition coils out of the wells they are plugged into, but followed TwoWheelObsessions instructions about twisting them around first, and then used a small pry bar (a cats paw) to gently break the seal. I am telling you this so you will understand that I am capable of working under there somewhat.
As an aside, I took photos of the TBS job as I was getting stuck, thinking they would illustrate the problem, but in fact they make it look easy , because I held the camera under the gas tank when taking the photos.
The bike is now running very well when hot, but sounds a bit weak on start up, like it might stall.
Thanks for reading, and any information would be most appreciated.
Ride Safe,
Cheers
I have just read many of the posts on this site, in my search for all the information I can get on how to do my first Throttle Body Synchronization. I am riding a 2016 Gen 4 fjr1300A.
I have a few questions, and they mostly are about the really nitty gritty little stuff that seems to be being left out. Here they are:
1. After raising the tank, to get at the throttle body nipples, I find that I cannot reach them all. Some are 5-6 inches below pipes and hoses on the surface of the motor, and very hard to reach. I'm pretty sure that I will have to remove the gas tank, then hook up the Carbtune, and then hook the gas tank back up, to get at the 4 necessary hose hook up locations. Has that been your experience?
Brian at TwoWheelObsession does a very good video on how to do a TBS, but he is working on a Gen3 2014 bike. I'm on Gen 4, and just don't see how I can do this without removing the tank to get at the necessary areas.
2. Also, I cannot find a suitable tool that will assure that I can get the little ring clips and black caps off without losing them into the abyss of the motor. Any tool suggestions?
3. The TBS adjusting screws are just forward of the rear of the gas tank, and face toward the rear of the gas tank. There is probably no more than 4-6 inches of room between the rear end of the gas tank, and the two inside TBS adjustment screws. With the engine nice and hot, as required to do a TBS properly, and the gas tank overhanging the work area, I just can not see me getting in there with out removing the tank, and having it hooked up , but out of the way. Does that sound right?
I replaced the plugs while I was under the tank, yesterday. That was the very first time I have done a spark plug change. I found it a little tricky getting the ignition coils out of the wells they are plugged into, but followed TwoWheelObsessions instructions about twisting them around first, and then used a small pry bar (a cats paw) to gently break the seal. I am telling you this so you will understand that I am capable of working under there somewhat.
As an aside, I took photos of the TBS job as I was getting stuck, thinking they would illustrate the problem, but in fact they make it look easy , because I held the camera under the gas tank when taking the photos.
The bike is now running very well when hot, but sounds a bit weak on start up, like it might stall.
Thanks for reading, and any information would be most appreciated.
Ride Safe,
Cheers
