air/fuel mixture adjustment?

Use the instructions for the 04, same for the 5. I used several strands taken from 14g wire, it's a tiny signal, so only needs tiny wire. I found that the bike liked a 5 step increase in colder weather, 3-4 in warm, this with D&D muffs and a foam Uni air filter.

For those that are unfamiliar with the linkage between the throttle bodies, the throttle cable is attached to the #3 throttle shaft. The #4 throttle shaft is connected to the #3 throttle shaft by way of two little springs. Similarly, #1 is connected to #2 and #2 is connected to #3. So when you twist the throttle, the cable does not open the butterfly on #1 directly. It opens #3, which applies pressure on the springs of #2 and eventually opens it, which applies pressure on the springs of #1 and eventually opens it.

Click to expand...

Thanks for the explanation. As one that is unfamiliar with the linkage and TBS, what you are describing sounds a lot like an old fashioned carb synch, at least when I used to do those I thought I was adjusting the butterflies (actually the slides) so they would all open at the same time. Now I am wondering what actually is being adjusted with a standard TBS?

The idle air bleed screws are what you adjust on a std TBS.

The idle air bleed screws are what you adjust on a std TBS.

Click to expand...

If that is all you adjust, it sounds like you are balancing the engine at idle and not much else -- what am I missing?

Thanks rad. I appreciate the info.

Ride safe.

The idle air bleed screws are what you adjust on a std TBS.

Click to expand...

If that is all you adjust, it sounds like you are balancing the engine at idle and not much else -- what am I missing?

Click to expand...

Bingo. I don't think you are missing anything.

The air bleed screws are a really fine adjustment that has a rapidly diminishing effect as the throttle opens. For perfect synch, it is necessary to zero in on the correct balance between throttle linkage adjustment and air bleed adjustment. To simplify, let us consider just one pair -- say #3 and #4. Let us assume that they are balanced at idle already, around 260 mmHg, but #4 vacuum is 30 mmHg high at 3,000 rpm. So we adjust the throttle linkage adjustment screw counter-clockwise to compensate (note that this is the opposite direction from most carburetted models for some reason) and return to idle. Now one will likely find that the idle synch is out with #4 being low -- say 15 mmHg low. Adjust the air bleed to synch them at idle and take it back up to 3,000 again. Now you will find #4 is high again -- perhaps 5 mmHg now. Eventually you can find the balance point where synch is perfect at all rpm.

Of course, it's a bit more complicated than that with 4 cylinders. I like to do all 4 at idle, then all 4 at 3k, etc.

One thing you may run into is a change in idle speed. In fact, a few folks who tried my suggestion found it climbed higher than they could tune out with the idle adjustment. Or they bottomed out the air bleed screws. Eventually a fellow by the name of Arlen Bloom found backing the individual stops down fixes both problems. He wrote an excellent MSWord how-to of the whole thing which is available here. I tried his modified procedure and it works well.

The idle air bleed screws are what you adjust on a std TBS.

Click to expand...

If that is all you adjust, it sounds like you are balancing the engine at idle and not much else -- what am I missing?

Click to expand...

The air bleed screws overlap the entire throttle range, but their effect gets less and less as the throttles are opened. They're designed to "trim" the TB's with the idea that the butterflys will stay synced well enough without adjustment. And idle is where any mis-sync is most noticeable, so according to Yamaha, it is the only place you really need to do the adjustment.

- Mark

The air bleed screws are a really fine adjustment that has a rapidly diminishing effect as the throttle opens.  For perfect synch, it is necessary to zero in on the correct balance between throttle linkage adjustment and air bleed adjustment.
One thing you may run into is a change in idle speed. In fact, a few folks who tried my suggestion found it climbed higher than they could tune out with the idle adjustment. Or they bottomed out the air bleed screws. Eventually a fellow by the name of Arlen Bloom found backing the individual stops down fixes both problems. He wrote an excellent MSWord how-to of the whole thing which is available.  I tried his modified procedure and it works well.

Click to expand...

Torch, Mark, thanks for the feedback, its nice to know what is really happening with those adjustments. There is a another active thread discussing vibrations above 4,000 rpms which has been one of my complaints about the FJR since I have owned it. I have had several big in-line fours and the FJR is the smoothest at 4,000 rpms and vibrates the most at 5,000 rpms. Several members have reported that they reduced the vibration above 4,000 rpms by synching the butterfiles but if the engine is smooth at 4,000 rpms (under a load) I would think the butterflies would have to be in synch at that point and have a hard time understanding how vibration above those rpms would be caused by the butterflies being out of synch.

Again, am I missing something?

Inline-four engines are known for being generally smooth, but having resonant buzziness at certain RPMs. It's really the nature of the beast and 1300cc is not a small four-cyl engine to be putting in a motorcycle.

5K is about the point where mine starts getting a little buzzy, but if I go ride any of my other bikes that are more serious shakers (e.g., my KTM LC4), when I come back to the FJR, I suddenly can't detect any vibration at any RPM. One's perception of vibration is really subjective.

Chasing the problem with tuning might be worth a try, but I wouldn't expect miracles. Most of our FJRs buzz a little because they're big inline fours, not because they're out of tune.

- Mark

Chasing the problem with tuning might be worth a try, but I wouldn't expect miracles.  Most of our FJRs buzz a little because they're big inline fours, not because they're out of tune.

Click to expand...

I have noted that several members have stated that using a PC with the Wally Smoothness Map did wonders for reducing vibration which would indicate the FJR's high rpm vibration is really the result of FI mapping or inaccurate FI sensors.

My personal experience is that the high rpm vibration pretty much went away over time, its still not as smooth at 5,000 rpms as it is at 4,000 rpms but the vibration is not annoying and I have to keep an eye on the speedometer to know how fast I am going -- and I don't have a clue why it is running so much smoother since the only thing I did was change the spark plugs at 7700 miles and did not notice any difference immediately after the spark plug change.

Chasing the problem with tuning might be worth a try, but I wouldn't expect miracles.  Most of our FJRs buzz a little because they're big inline fours, not because they're out of tune.

Click to expand...

I have noted that several members have stated that using a PC with the Wally Smoothness Map did wonders for reducing vibration which would indicate the FJR's high rpm vibration is really the result of FI mapping or inaccurate FI sensors.

Click to expand...

FJR's mostly vibrate because they're a big 1300cc inline-four engine in a motorcycle chassis, not because of FI mapping or sensor glitches.

Now I'm not saying that tweaking doesn't make a difference and certainly it can make a huge difference if the bike is out of tune or has a problem to begin with. But for the average bike, it's marginal. And riders, after spending a lot of money and time on a fix, are highly pre-disposed to think they've made a major improvement, especially with something as subjective as vibration.

It's like exhaust systems - virtually everyone thinks they're bike is faster with an aftermarket exhaust. But the non-butt-dyno usually says otherwise.

- Mark

>>FJR's mostly vibrate because they're a big 1300cc inline-four engine in a motorcycle chassis, not because of FI mapping or sensor glitches.<<

Why is it then that you don't read about buzziness in the Honda Blackbird or the new Kawasaki ZX14? My FJR buzzes enough that it pretty much kills the upper power band's use. If I can't get this sorted out, I'll be dropping this bike for something else next year. I never get rid of stuff this soon. I usually keep things for or five years minimum.

EDIT: You know... I may have spoken out too soon on this. My bike now has 2500 miles on it and I think it's getting quite a bit smoother of late. Me likey.

Dan23 said:

>>FJR's mostly vibrate because they're a big 1300cc inline-four engine in a motorcycle chassis, not because of FI mapping or sensor glitches.<<
Why is it then that you don't read about buzziness in the Honda Blackbird or the new Kawasaki ZX14? My FJR buzzes enough that it pretty much kills the upper power band's use. If I can't get this sorted out, I'll be dropping this bike for something else next year. I never get rid of stuff this soon. I usually keep things for or five years minimum.

EDIT: You know... I may have spoken out too soon on this. My bike now has 2500 miles on it and I think it's getting quite a bit smoother of late. Me likey.

Click to expand...

The Blackbird is smooth... the ZX-11, ZZR-1200 and that line have their own buzzes in certain RPM ranges. I haven't ridden a ZX-14 yet but I'd expect about the same from the same family of motor. It kicks in around 6k.

But yes, In my opinion it's a different buzz, than the buzz of the FJR... Maybe Honda just isolated the rider better on the blackbird. Kawi isn't known for their refinement

While the buzz in my FJR isn't hateful, I'd like it to be less too. I'm sure I'll get used to it. We'll see.

This thread though is chock full of awesome info. I think I'll pass on the barb-mod, and maybe go with a PowerCommander down the road.

I will also re-think how I sync the throttle bodies after reading that doc.

[SIZE=12pt]Synchronizing the FJR Throttle Body Linkages[/SIZE]



Adjusting the TB air screws alone does not provide the most effective TB sync because they only compensate for air flow at idle. Most of your riding takes place at higher RPMs. The throttle valves (butterflies) of each throttle body need to be in sync with each other at high (off-idle) RPM.

This procedure is not covered in the factory manual. However this procedure is common and dealers that know what they are doing (and are willing to take the time) perform this adjustment on many multi-cylinder bikes. Having the TB’s in sync at cruising speeds (not just at idle) makes a huge difference in engine smoothness and vibration.

You should not have to adjust the individual throttle stop screws to achieve this. This assumes that the throttle stop screws have not been grossly misadjusted at the factory (guy on the flow bench had one too many bottles of Sapporo the night before) or the lock nuts have come loose.

To get the engine’s intake tracks in sync the four throttle body linkages need to be adjusted. The throttle bodies are linked in pairs. TB’s #1 & #2 are one pair and #3 & #4 are the other pair—finally the two pairs are adjusted together (#1 & #2 and #3 & #4).

This is a simple procedure but does take patience. The image shows TB #1 on the left and the linkage adjustment screws are circled. Here is what I did to get my FJR in sync.

1) Get the engine hot by going for a short ride. When you are at 4200 RPM in 3rd or 4th gear, squeeze you heals against the frame to feel the level of engine vibration. This highly precise measurement will be used later to determine how good a sync job you did.

2) Raise Tank and connect sync tool.

3) Turn all four air adjusting screws in until they are lightly seated.

4) Back each screw out 1 turn

5) You may want to place a large fan in front of the radiator to keep things cool (including you).

6) Start the engine.

7) The TBs will probably be out of sync to some extent but not more than 1 to 4 cm of Hg. The actual vacuum level does not matter. If they are out more than this keep going through these steps—we’ll fix this later in the procedure.

8) REVING THE ENGINE Slowly rev the engine up to around 4000 RPM while watching your sync tool. What you are looking for is even vacuum levels as engine speed increases. If you try to perform to sync the TBs with the engine speed steady (say at 4000 RPM) you will find that the vacuum levels between each TB will never be in sync no matter how many adjustments you make. It is more important for vacuum levels to be even during moderate, smooth, engine acceleration and not at a steady throttle setting.

9) Using the butterfly sync screw between TBs #3 and #4 (Yellow Circle) adjust the vacuum level so #3 and #4 are the same when you accelerate the engine as described in step 8, “REVING THE ENGINE above. This will take several tries. You may not get them exactly even either, but get them as close as you can (usually within 1 cm of Hg.).

10) Now perform the same procedure on TBs #1 and #2 (Green Circle). You may have to rev the engine half a dozen times to get them close.

11) With vacuum levels for TB pairs #1/#2 and #3/#4 matched it’s time to sync the two pairs of TBs together.

12) Rev the engine as described in step 8, REVING THE ENGINE while watching the two pairs of TBs. If they are off by more than 1 cm of Hg., an adjustment is needed.

13) The adjustment screw can only be accessed with the engine off. The screw is located between the two pairs of TBs (Blue Circle with Arrow). (The throttle has to be opened about ¾ of a turn to get a screw driver on the screw). Turn the screw about 1/8 of a turn (either direction) and restart the engine.

14) Check the balance (vacuum level) between the two pairs of TBs. Shut the engine off and readjust as many times as needed. (By now you and your FJR’s cooling system will appreciate the large fan you are using, step 5.)

15) When the two pairs of TBs are even (when you smoothly rev the engine) you are finished with this step.

16) Now let the engine idle. Adjust the idle speed to 1000. The tach on the FJR is very accurate. I checked it against a $500 electronic sync tool that counts the vacuum pulses during the intake stroke of cyl #1 and then generates an RPM signal on the tool.

17) Now it’s time (finally) to adjust the airscrews on each TB. Use cyl #3 as reference and adjust the other cylinders to the same vacuum level as #3. The actual level does not matter (I know, everyone seems to be hung up on how may cm of HG., but it really doesn’t matter as long as idle speed is kept at 1000 RPM.)

18) Make a final idle adjustment (1000 RPM) and you done. If after syncing the TBs with the airscrews you can’t get the idle speed to come down to 1000 rpm, DON’T KEEP BACKING THE IDLE ADJUSTING SCREW OUT. The TB airscrews all need to be turned in ½ turn. Now the idle adjusting screw will allow you to adjust the idle speed to down to 1000 rpm.

19) Go for a ride and check engine vibration at 4200 RPM (Step 1), it should be better than when you started. If it’s worse, you screwed up the adjustment. The amount of improvement really depends on how far out of the sync the TB linkage was before you started. When done correctly most of the vibration you normally feel at 4100/4200 RPM in fourth/fifth gear should be gone—at least it was on my 2005. Good Luck!

Nice writeup 3dogs! Useful picture too. I need to do this version the next time I'm under the tank...

Yo 3dogs - you going to WFO?

If so, I bestow upon you the honor of doing your neat-o little procedure to my FJR.

Deal?

SkooterG, I can't go to the WFO this year. Next year I hope to teach the Total Control Riding class there. I recall that you had tried the accelleator pump software with your PCIII. If so, what settings did you use and was it worth doing. Send me an email if you like. [email protected]

3dogs said:

SkooterG, I can't go to the WFO this year. Next year I hope to teach the Total Control Riding class there. I recall that you had tried the accelleator pump software with your PCIII. If so, what settings did you use and was it worth doing. Send me an email if you like. [email protected]

Click to expand...

Sorry to hear you won't be at WFO.

Hey, I did reply to the email you sent me a few weeks back.............

I have never tried the accellerator pump function of the PCIII. I've heard it puts a smile on your face, and sucks the gas big time. One of these days I will have to give it a try. Sorry I can't help. I think Jestal would be good to talk to. I believe he has tried it, and of course is knowledgeable about these things.

And then there is radman - Yo radman, you ever tried the accellerator pump option on the PCIII?

3dogs said:

[SIZE=12pt]Synchronizing the FJR Throttle Body Linkages[/SIZE]

Adjusting the TB air screws alone does not provide the most effective TB sync because they only compensate for air flow at idle. Most of your riding takes place at higher RPMs. The throttle valves (butterflies) of each throttle body need to be in sync with each other at high (off-idle) RPM.

This procedure is not covered in the factory manual. However this procedure is common and dealers that know what they are doing (and are willing to take the time) perform this adjustment on many multi-cylinder bikes. Having the TB’s in sync at cruising speeds (not just at idle) makes a huge difference in engine smoothness and vibration.

You should not have to adjust the individual throttle stop screws to achieve this. This assumes that the throttle stop screws have not been grossly misadjusted at the factory (guy on the flow bench had one too many bottles of Sapporo the night before) or the lock nuts have come loose.

To get the engine’s intake tracks in sync the four throttle body linkages need to be adjusted. The throttle bodies are linked in pairs. TB’s #1 & #2 are one pair and #3 & #4 are the other pair—finally the two pairs are adjusted together (#1 & #2 and #3 & #4).

This is a simple procedure but does take patience. The image shows TB #1 on the left and the linkage adjustment screws are circled. Here is what I did to get my FJR in sync.

1) Get the engine hot by going for a short ride. When you are at 4200 RPM in 3rd or 4th gear, squeeze you heals against the frame to feel the level of engine vibration. This highly precise measurement will be used later to determine how good a sync job you did.

2) Raise Tank and connect sync tool.

3) Turn all four air adjusting screws in until they are lightly seated.

4) Back each screw out 1 turn

5) You may want to place a large fan in front of the radiator to keep things cool (including you).

6) Start the engine.

7) The TBs will probably be out of sync to some extent but not more than 1 to 4 cm of Hg. The actual vacuum level does not matter. If they are out more than this keep going through these steps—we’ll fix this later in the procedure.

8) REVING THE ENGINE Slowly rev the engine up to around 4000 RPM while watching your sync tool. What you are looking for is even vacuum levels as engine speed increases. If you try to perform to sync the TBs with the engine speed steady (say at 4000 RPM) you will find that the vacuum levels between each TB will never be in sync no matter how many adjustments you make. It is more important for vacuum levels to be even during moderate, smooth, engine acceleration and not at a steady throttle setting.

9) Using the butterfly sync screw between TBs #3 and #4 (Yellow Circle) adjust the vacuum level so #3 and #4 are the same when you accelerate the engine as described in step 8, “REVING THE ENGINE above. This will take several tries. You may not get them exactly even either, but get them as close as you can (usually within 1 cm of Hg.).

10) Now perform the same procedure on TBs #1 and #2 (Green Circle). You may have to rev the engine half a dozen times to get them close.

11) With vacuum levels for TB pairs #1/#2 and #3/#4 matched it’s time to sync the two pairs of TBs together.

12) Rev the engine as described in step 8, REVING THE ENGINE while watching the two pairs of TBs. If they are off by more than 1 cm of Hg., an adjustment is needed.

13) The adjustment screw can only be accessed with the engine off. The screw is located between the two pairs of TBs (Blue Circle with Arrow). (The throttle has to be opened about ¾ of a turn to get a screw driver on the screw). Turn the screw about 1/8 of a turn (either direction) and restart the engine.

14) Check the balance (vacuum level) between the two pairs of TBs. Shut the engine off and readjust as many times as needed. (By now you and your FJR’s cooling system will appreciate the large fan you are using, step 5.)

15) When the two pairs of TBs are even (when you smoothly rev the engine) you are finished with this step.

16) Now let the engine idle. Adjust the idle speed to 1000. The tach on the FJR is very accurate. I checked it against a $500 electronic sync tool that counts the vacuum pulses during the intake stroke of cyl #1 and then generates an RPM signal on the tool.

17) Now it’s time (finally) to adjust the airscrews on each TB. Use cyl #3 as reference and adjust the other cylinders to the same vacuum level as #3. The actual level does not matter (I know, everyone seems to be hung up on how may cm of HG., but it really doesn’t matter as long as idle speed is kept at 1000 RPM.)

18) Make a final idle adjustment (1000 RPM) and you done. If after syncing the TBs with the airscrews you can’t get the idle speed to come down to 1000 rpm, DON’T KEEP BACKING THE IDLE ADJUSTING SCREW OUT. The TB airscrews all need to be turned in ½ turn. Now the idle adjusting screw will allow you to adjust the idle speed to down to 1000 rpm.

19) Go for a ride and check engine vibration at 4200 RPM (Step 1), it should be better than when you started. If it’s worse, you screwed up the adjustment. The amount of improvement really depends on how far out of the sync the TB linkage was before you started. When done correctly most of the vibration you normally feel at 4100/4200 RPM in fourth/fifth gear should be gone—at least it was on my 2005. Good Luck!

Click to expand...

Outstanding write up 3Dogs, :clapping: I have 4200 miles on my FJR and need to sync the throttle bodies before I ride this season, Thank You.

3dogs said:

[SIZE=12pt]Synchronizing the FJR Throttle Body Linkages[/SIZE]

Adjusting the TB air screws alone does not provide the most effective TB sync because they only compensate for air flow at idle. Most of your riding takes place at higher RPMs. The throttle valves (butterflies) of each throttle body need to be in sync with each other at high (off-idle) RPM.

This procedure is not covered in the factory manual. However this procedure is common and dealers that know what they are doing (and are willing to take the time) perform this adjustment on many multi-cylinder bikes. Having the TB’s in sync at cruising speeds (not just at idle) makes a huge difference in engine smoothness and vibration.

You should not have to adjust the individual throttle stop screws to achieve this. This assumes that the throttle stop screws have not been grossly misadjusted at the factory (guy on the flow bench had one too many bottles of Sapporo the night before) or the lock nuts have come loose.

To get the engine’s intake tracks in sync the four throttle body linkages need to be adjusted. The throttle bodies are linked in pairs. TB’s #1 & #2 are one pair and #3 & #4 are the other pair—finally the two pairs are adjusted together (#1 & #2 and #3 & #4).

This is a simple procedure but does take patience. The image shows TB #1 on the left and the linkage adjustment screws are circled. Here is what I did to get my FJR in sync.

1) Get the engine hot by going for a short ride. When you are at 4200 RPM in 3rd or 4th gear, squeeze you heals against the frame to feel the level of engine vibration. This highly precise measurement will be used later to determine how good a sync job you did.

2) Raise Tank and connect sync tool.

3) Turn all four air adjusting screws in until they are lightly seated.

4) Back each screw out 1 turn

5) You may want to place a large fan in front of the radiator to keep things cool (including you).

6) Start the engine.

7) The TBs will probably be out of sync to some extent but not more than 1 to 4 cm of Hg. The actual vacuum level does not matter. If they are out more than this keep going through these steps—we’ll fix this later in the procedure.

8) REVING THE ENGINE Slowly rev the engine up to around 4000 RPM while watching your sync tool. What you are looking for is even vacuum levels as engine speed increases. If you try to perform to sync the TBs with the engine speed steady (say at 4000 RPM) you will find that the vacuum levels between each TB will never be in sync no matter how many adjustments you make. It is more important for vacuum levels to be even during moderate, smooth, engine acceleration and not at a steady throttle setting.

9) Using the butterfly sync screw between TBs #3 and #4 (Yellow Circle) adjust the vacuum level so #3 and #4 are the same when you accelerate the engine as described in step 8, “REVING THE ENGINE above. This will take several tries. You may not get them exactly even either, but get them as close as you can (usually within 1 cm of Hg.).

10) Now perform the same procedure on TBs #1 and #2 (Green Circle). You may have to rev the engine half a dozen times to get them close.

11) With vacuum levels for TB pairs #1/#2 and #3/#4 matched it’s time to sync the two pairs of TBs together.

12) Rev the engine as described in step 8, REVING THE ENGINE while watching the two pairs of TBs. If they are off by more than 1 cm of Hg., an adjustment is needed.

13) The adjustment screw can only be accessed with the engine off. The screw is located between the two pairs of TBs (Blue Circle with Arrow). (The throttle has to be opened about ¾ of a turn to get a screw driver on the screw). Turn the screw about 1/8 of a turn (either direction) and restart the engine.

14) Check the balance (vacuum level) between the two pairs of TBs. Shut the engine off and readjust as many times as needed. (By now you and your FJR’s cooling system will appreciate the large fan you are using, step 5.)

15) When the two pairs of TBs are even (when you smoothly rev the engine) you are finished with this step.

16) Now let the engine idle. Adjust the idle speed to 1000. The tach on the FJR is very accurate. I checked it against a $500 electronic sync tool that counts the vacuum pulses during the intake stroke of cyl #1 and then generates an RPM signal on the tool.

17) Now it’s time (finally) to adjust the airscrews on each TB. Use cyl #3 as reference and adjust the other cylinders to the same vacuum level as #3. The actual level does not matter (I know, everyone seems to be hung up on how may cm of HG., but it really doesn’t matter as long as idle speed is kept at 1000 RPM.)

18) Make a final idle adjustment (1000 RPM) and you done. If after syncing the TBs with the airscrews you can’t get the idle speed to come down to 1000 rpm, DON’T KEEP BACKING THE IDLE ADJUSTING SCREW OUT. The TB airscrews all need to be turned in ½ turn. Now the idle adjusting screw will allow you to adjust the idle speed to down to 1000 rpm.

19) Go for a ride and check engine vibration at 4200 RPM (Step 1), it should be better than when you started. If it’s worse, you screwed up the adjustment. The amount of improvement really depends on how far out of the sync the TB linkage was before you started. When done correctly most of the vibration you normally feel at 4100/4200 RPM in fourth/fifth gear should be gone—at least it was on my 2005. Good Luck!

Click to expand...

I just got done doing this TBS and I have a question or two....

I noticed when doing this that the vacuum difference was over 10 to start with. It seems like I could either adjust the vacuum to be equal but then the rate of change would be off, or adjust it for the rate of change to be equal and the vacuum levels to be off. So I kinda split the difference and I don't think I should have done it that way. I think I should have made the rate of change equal, Then equalize the vacuum levels with the air screws. Is that right? Or am I way off in my thinking?