Any one with a Gen III planning on doing a TB sync shortly?

[pcarnut]

Been working to try and dial out an off idle stumble/surge I have with my '14 with not much success. Due to an out of whack manometer while doing a TB sync recently I ended up adjusting my #1 air screw (I know I know, was supposed to change it) and didn't count how many turns out it was first.

I was hoping someone might be willing to see what their air screw (the one with the white paint) is set at so I have a rough idea where I should be. In searching old threads I read one that said if the air screws have been removed, to set them 1 turn out as a starting point. This sound right? Any help would be hugely appreciated!!! Thanks, Roger

 

[escapefjrtist]

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.

FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

 

[pcarnut]

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.
FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

Thanks, this would seem to support what I read. I seem to recall my original setting was either bottomed out or very close to it. I've done the TB sync about 5 times now, gradually opening up the number 1 screw from fully closed. Right now it's about 1/3 turn out and a little better but tried 1/2 a turn out and no further improvement so went back to 1/3 turn. Guess I'll have to just try 1 full turn out and see what happens.

 

[SkooterG]

What is your idle speed? Possibly set too low?

 

[escapefjrtist]

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.

FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

Thanks, this would seem to support what I read. I seem to recall my original setting was either bottomed out or very close to it. I've done the TB sync about 5 times now, gradually opening up the number 1 screw from fully closed. Right now it's about 1/3 turn out and a little better but tried 1/2 a turn out and no further improvement so went back to 1/3 turn. Guess I'll have to just try 1 full turn out and see what happens.

FWIW before going further, I think I'd go back to 1/3 turn out and stop. Make sure you have a solid TBS with known good equipment, ride it a few hundred [thousand] miles and then readdress if needed.

Good luck!

--G

 

[escapefjrtist]

What is your idle speed? Possibly set too low?

Can the idle speed be tweaked with the RBW??

--G

 

[pcarnut]

What is your idle speed? Possibly set too low?

Idle seems good, around 1050-1100. My understanding was that the idle speed is non adjustable on the Gen III?

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.

FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

Thanks, this would seem to support what I read. I seem to recall my original setting was either bottomed out or very close to it. I've done the TB sync about 5 times now, gradually opening up the number 1 screw from fully closed. Right now it's about 1/3 turn out and a little better but tried 1/2 a turn out and no further improvement so went back to 1/3 turn. Guess I'll have to just try 1 full turn out and see what happens.

FWIW before going further, I think I'd go back to 1/3 turn out and stop. Make sure you have a solid TBS with known good equipment, ride it a few hundred [thousand] miles and then readdress if needed.

Good luck!

--G

This is actually where I'm at. I bought a new manometer and have compared it with a Morgan Carbtune unit so pretty sure I'm good now on equipment and bike is very smooth otherwise. I've gone about 5-600 miles at 1/3 out and the stumble is still there. Feels like my '07 before I installed the PCV.

 

[pcarnut]

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.
FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

Did backing out the screw help with the stumble?

 

[gregory]

According to this guy, Cyl 1 is synced to the computer and should not be changed at all. Perhaps one of the gurus can speak to this. Most of the video is how to get under the tank. He talks about using #1 around the 19:10 mark. Could be that you need to re-sync to the computer?

https://twowheelobsession.com/2014/08/27/throttle-body-sync-tbs-yamaha-fjr-1300-es/

 

[pcarnut]

Saw the video, not sure what he is basing that statement on.

 

[Bungie]

Turn in one of the other mixture screws until it light seats while counting precisely the number of turns. Then back it back out that number turns.

Turn in number 1 until it lightly seats, then back it out the same. By looking at the white paint and aligning them at that point, you should be able to get them within an RCH of being exactly where it was to start.

It's pretty rare to have one of the screws (on a properly setup up bike) differing more than half a turn from the other screws.

 

[Kaelaria]

I said in the video...look to see which one is painted. In my case it's was #1, others vary, check what your particular manual says.

 

[Just Krusen]

When I did the sync on my bike the #1 was painted and I did not touch it. I did notice that the #2 was set just barley cracked from fully seated. Did not notice if 3 & 4 were that close.

 

[escapefjrtist]

Are you sure it wasn't bottomed out? Unless the FSM says something to the contrary, I'd start with 1 to 1-1/2 turns out and adjust from there.

FYI, my Tenere also has a white painted air screw that [is] was bottomed and not supposed to be changed. To help with the Tenere off idle stumble, one of the mods is to back out the white painted air screw 3/4 turn and then match the other side to it. I did it...don't know if it helped or not but the engine hasn't blown up yet...

--G

Did backing out the screw help with the stumble?

Hard to tell. I had a very slight stumble off idle and after some reading, thought I'd give it a whirl. Idle quality "seemed" to be improved, but then again, idle improved as the miles piled up. Probably the placebo effect more than anything...

--G

 

[Bustanut joker]

And this has been hashed out how many times in the past?

Come on noobs read the **** you was told when ya signed up. Ok so genlll might not be specified,it ain't rocket science.

 

[pcarnut]

Turn in one of the other mixture screws until itght seats while counting precisely the number of turns. Then back it back out that number turns.

Turn in number 1 until it lightly seats, then back it out the same. By looking at the white paint and aligning them at that point, you should be able to get them within an RCH of being exactly where it was to start.

It's pretty rare to have one of the screws (on a properly setup up bike) differing more than half a turn from the other screws.

Great suggestion! I'm diving back in tomorrow on this. I'll either try backing out the # 1 one turn or doing what you suggest, either way it give me something to try, cause I'm stumped right now.

I said in the video...look to see which one is painted. In my case it's was #1, others vary, check what your particular manual says.

Mine is number 1 also, as are all the Gen IIIs I believe, but no matter, number 1 is my painted one.

Thanks guys for all the help!! Really appreciate it. Just put on a new set of Angels tonight so if nothing else I'll have a nice handling stuttering bike.

 

[Fred W]

It really doesn't matter which one is the reference. You just want all 4 to be at the same vacuum. The Idle speed is automatically controlled by the ECU on 3rd gens. The only time you'd run into idle speed problems is if you cranked them all in too far or out too far.

I suspect that they paint the white dot on whichever cylinder has the lowest vacuum after they are all opened a predetermined amount (like 1/3 turn) or maybe when they are all closed fully. That way the other 3 can all just be opened up a little to match it.

 

[pcarnut]

It really doesn't matter which one is the reference. You just want all 4 to be at the same vacuum. The Idle speed is automatically controlled by the ECU on 3rd gens. The only time you'd run into idle speed problems is if you cranked them all in too far or out too far.
I suspect that they paint the white dot on whichever cylinder has the lowest vacuum after they are all opened a predetermined amount (like 1/3 turn) or maybe when they are all closed fully. That way the other 3 can all just be opened up a little to match it.

What you suggest makes perfects sense but the stumble is not going away with the #1 screw any where from seated to 1/2 turn out and then the others re-synced accordingly. Several times the bike has run very smoothly for up to about 100 miles and is seemingly back to normal, only to start stumbling again. Yesterday I tried #1 at one turn out as suggested, reset the others and went for about 80 miles, and again, all seemed well until about the 40-50 mile mark and I started getting a very slight surge but not as bad as previous times.

The stumble was very slight so I'm going to live with it for a few more days and see. This issue makes no sense to me though. Why should it seem fine after initial sync and then the stumble creep in again? Been trying to figure if I've affected something else in the adjustment process, maybe fuel filter plugging up with all the tipping up and down of the tank? Bike has only 14k miles so this seems unlikely. Also ran some Techron through it in hopes maybe it was water in the system, also replaced the plugs, but no joy. Thanks for your input though, any thoughts are greatly appreciated.

 

[sme]

Have you checked your TPS? With the diag code it's easy to do.