Throttle Body Synch-time - Which way?

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Had an old Motion Pro economy model for a few years; just replaced it this year with a Carbtune that I bought online from the U.K. Delivery was pretty quick. I like the Carbtune a lot. Even with a weak U.S. dollar, I think it's quality makes it a good value.
Why did you replace the old one? Lose the mercury out of it? Does the Carbtune work better?

I'm still using mine that I've had for many years and it still works great, is why I'm asking. Of course, I can understand wanting to get the latest and greatest. ;)

 
One added point:
[blasphemy]

You could probably get away without doing a TBS ever. Assuming that all you are ever doing is the "authorized" version of TBS where one adjusts the air screws on the throttle bodies at idle, this maintenance item will have negligible effect on how your bike actually runs at anything above idle. The air screws adjust the air flow through a small circuit in the body that bypasses the throttle plate (butterfly valve). When the plate is fully closed at idle these bypass circuits represent a significant amount of the total intake air, so adjusting them will allow you to balance the vacuum in each intake. However, as you crack open the throttle that tiny air path is of increasing less significance.

Many folks report getting a smoother running engine after having done a TBS, but I think that is either a case of them having done other maintenance items coincidentally (plugs, air filter, etc) or just good ole' placebo effect.

Attempting to adjust out the "buzz" that most bikes have at ~ 4k rpm by adjusting the air screws doesn't make any sense.

[/blasphemy]

What does make sense for that is to adjust the throttle plates to open in perfect synchronization since they will have the greatest effect on the throttle balance during open throttle conditions. The problem people run into when attempting the unauthorized TBS procedure is they end up chasing the adjustment between the air screws and throttle plates as there is some small amount of inter-dependence.

A better way to do this would be to close down all 4 of the air screws first, then start the bike. You'll need to use a throttle lock to get the bike to idle as you closed off all the bypass air. This means that only air going through the throttle plates will get to the engine. That way you can balance the plates (at idle) where the vacuum will be the most effected by small differences in the angle of the plates. No need to try to make the adjustment at 4k rpm, though you can easily check it if you want. If they are balanced at idle they should be balanced as the throttle opens. When you are happy with the plates open all 4 air screws an equal amount (~ 2 turns) and then re-balance them at idle as normal.

Now FredW, this reads very good. However I am going to have to print, and study a couple times to get the full gist of the idea, but certianly reads as a very reasonable way to attack a sync issue.

Thanks a bunch for this, obviously I will try this method first...As the bike doesn't seem to have any ill effects, but trying to follow schedule.

 
The vibes I referred to earlier was for my 07 FZ6 inbetween 4-5k RPM. It vibrated sharply, intensely, mostly thru the seat at 40-50 MPH (causing eventual numbness).

I could adjust the air screws to have them right on the money at idle (1300RPM) and then bring the rev's up to 4k and hold it and see one cylinder pulling slightly harder. I re-adjusted to get them level at 4k and at idle, with no other mod's changes, etc, and got rid of 80% of the vibes. Now this bike does rev considerbly higher than the FJR, 14,000 RPMs so its not as if I'm adjusting air screws at half throttle... In either case, this did in fact work for me...

This was the first sync done on this bike with 5k miles on the clock... Other riders on the FZ forum I also frequent

( https://www.fz6-forum.com/forum/cmps_index.php ) posted similar results. The vibes in my FJR are not bad, nor were they on my old 2000 ZRX 1100, so I am familiar with vibes assosiated with in line 4's.

Scott

 
Another carbtune here. I loan it to friends all the time and have made back most of its cost in gratuities.

 
A better way to do this would be to close down all 4 of the air screws first, then start the bike. You'll need to use a throttle lock to get the bike to idle as you closed off all the bypass air. This means that only air going through the throttle plates will get to the engine. That way you can balance the plates (at idle) where the vacuum will be the most effected by small differences in the angle of the plates. No need to try to make the adjustment at 4k rpm, though you can easily check it if you want. If they are balanced at idle they should be balanced as the throttle opens. When you are happy with the plates open all 4 air screws an equal amount (~ 2 turns) and then re-balance them at idle as normal.
Fred,

Have you tried this? The logic, at least on the surface, sounds impeccable.

This is worth a thread all by itself, if you ask me, since it makes more sense than the Unauthorized version at 4K, or the modified Unauthorized version, from Jestall IIRC, simulating a load by killing a cylinder by unplugging an injector. Or was it Radman? Too lazy to search.

Did this idea recently come to you, or have you been saving it to give it to the forum as a Christmas gift?

 
I just use that "dangerous" silver liquid that's going to wipe out mankind.. :eek: Hey nuttin' to wear out,stick, or fall apart.

JMHO

:jester:

 
A better way to do this would be to close down all 4 of the air screws first, then start the bike. You'll need to use a throttle lock to get the bike to idle as you closed off all the bypass air. This means that only air going through the throttle plates will get to the engine. That way you can balance the plates (at idle) where the vacuum will be the most effected by small differences in the angle of the plates. No need to try to make the adjustment at 4k rpm, though you can easily check it if you want. If they are balanced at idle they should be balanced as the throttle opens. When you are happy with the plates open all 4 air screws an equal amount (~ 2 turns) and then re-balance them at idle as normal.
Fred,

Have you tried this? The logic, at least on the surface, sounds impeccable.

This is worth a thread all by itself, if you ask me, since it makes more sense than the Unauthorized version at 4K, or the modified Unauthorized version, from Jestall IIRC, simulating a load by killing a cylinder by unplugging an injector. Or was it Radman? Too lazy to search.

Did this idea recently come to you, or have you been saving it to give it to the forum as a Christmas gift?

Howie,

No, I have not actually done this procedure yet. I have attempted the standard UA TBS synch and was less than satisfied with the results for two reasons. One was because I was using a TwinMax vacuum gauge, which only has two channels. This made the process tediously iterative, plugging and unplugging vacuum lines. The other is because I think the procedure is flawed due to the co-dependence of the air screw settings and the throttle plate angles on the measured vacuum.

Much as I would like to take credit for it, this idea (closing down the air screws fully) is not my own. It came out of an online discussion with (short time) forum member Alakso here . Later, in this thread he detailed how this worked successfully to do exactly what we are talking about.

I intend on getting myself a 4-channel vacuum gauge over the winter. When I do, I will use this method to check the throttle plate sync and detail the full procedure (with pictures of course) for posterity.

Like you said, it just makes too much sense not to work right. ;)

 
Ok, I've done my TBS using the Morgan as well. I did it only at idle cuz the one involving throttle plates is still a lil too challenging for me, at least for now.

Question 1, I did TBS once with an experienced friend 6 years ago. I meddled with the air screws but it failed to fully synchronize the TB. Being new to EFI engines, my friend suggested using the throttle adjustment screws method which has always been the norm to him. We went ahead and it did. However, I left the air screws as its is and some were in the fully in position (or the other way round).

After sending my bike for servicing, my mech told me not to use the air screws for adjustment. He said some of my cylinders were too hot and my plugs showed signs of overheating.

So izit true thats the cause?

Question 2, I setup the carbtune as per the manual. It said to install the restrictors att least 90 cm away from the gauge given 1m hoses. I installed it at 91 cm away but still find the readings fluctuating quite a bit.



Izit just me?

 
Ok, I've done my TBS using the Morgan as well. I did it only at idle cuz the one involving throttle plates is still a lil too challenging for me, at least for now.
Question 1, I did TBS once with an experienced friend 6 years ago. I meddled with the air screws but it failed to fully synchronize the TB. Being new to EFI engines, my friend suggested using the throttle adjustment screws method which has always been the norm to him. We went ahead and it did. However, I left the air screws as its is and some were in the fully in position (or the other way round).

After sending my bike for servicing, my mech told me not to use the air screws for adjustment. He said some of my cylinders were too hot and my plugs showed signs of overheating.

So izit true thats the cause?

Question 2, I setup the carbtune as per the manual. It said to install the restrictors att least 90 cm away from the gauge given 1m hoses. I installed it at 91 cm away but still find the readings fluctuating quite a bit.


What you did was completely wrong, and so is your mechanic.

As has been said many times, the adjustment you should (normally) be making at idle is the air screws. That is because the air screws have their primary effect at idle with a progressively decreasing effect as the throttle plates are opened. You adjusted the angles of the throttle plates at idle (with the air screws all over the place). Yes they will have an effect at idle, as is evidenced by your ability to get the vacuums balanced, but as you advance the throttle off of the idle position (ie as the air screws' effect is diminished) the throttle plate adjustment becomes the primary means of balance.

What this means is that you have misadjusted your throttle plates to compensate for your air screws to get a balanced vacuum at idle. But when you go off idle the balance will be bad. You can check that just by revving the engine up some with the vacuum gauge attached. This is also the most likely reason for some of your cylinders running lean. The Fuel injection can't actually adjust to individual cylinders since, even in closed loop mode, the O2 sensor looks at the combined (average) exhaust gas, the FI will send fuel to compensate for the average. With your throttle plates mis-adjusted some cylinders will be run leaner (more air) others richer for the given point in the fuel map.

The way to get the throttle plates re-balanced will be to first remove any variation in the air supplied by the air screws, and then re-adjusting the throttle plate angles as you just did. Since we can't be 100% sure that the air supplied will be exactly equal in every cylinder at some arbitrary opening (ie all at 1.5 turns open) you may want to try my suggestion of closing all of the air screws completely and raising the idle artificially. Even just setting the air screws all to 1.5 turns out and then re-balancing the plates would be better than what you have right now.

BTW - having the gauge bounce a little like in your video is perfectly normal. You just average the readings with your eye-ball. Yours looked perfectly balanced in the video.

 
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Ok, I've done my TBS using the Morgan as well. I did it only at idle cuz the one involving throttle plates is still a lil too challenging for me, at least for now.
Question 1, I did TBS once with an experienced friend 6 years ago. I meddled with the air screws but it failed to fully synchronize the TB. Being new to EFI engines, my friend suggested using the throttle adjustment screws method which has always been the norm to him. We went ahead and it did. However, I left the air screws as its is and some were in the fully in position (or the other way round).

After sending my bike for servicing, my mech told me not to use the air screws for adjustment. He said some of my cylinders were too hot and my plugs showed signs of overheating.

So izit true thats the cause?

Question 2, I setup the carbtune as per the manual. It said to install the restrictors att least 90 cm away from the gauge given 1m hoses. I installed it at 91 cm away but still find the readings fluctuating quite a bit.



Ok, ur getting me confused just a lil.. This TBS sync that I've just performed is done purely using air screws at idle..

So lets just say I want to zero out things and start all over, can I use the unathourise TBS by Arlen Bloom?

 
Omni,

You sure can. I did it as well. I believe you Close #3 all the way down and back out 1 Turn as a Baseline.

This one takes times but if done right, it will run sooo well.

Good Luck!

 
A better way to do this would be to close down all 4 of the air screws first, then start the bike. You'll need to use a throttle lock to get the bike to idle as you closed off all the bypass air. This means that only air going through the throttle plates will get to the engine. That way you can balance the plates (at idle) where the vacuum will be the most effected by small differences in the angle of the plates. No need to try to make the adjustment at 4k rpm, though you can easily check it if you want. If they are balanced at idle they should be balanced as the throttle opens. When you are happy with the plates open all 4 air screws an equal amount (~ 2 turns) and then re-balance them at idle as normal.

This is the way I have been doing it and works well. I lock the throttle around 1200 RPM and the bodies are still synched at higher RPM's.

 
Ok, ur getting me confused just a lil.. This TBS sync that I've just performed is done purely using air screws at idle..
So lets just say I want to zero out things and start all over, can I use the unathourise TBS by Arlen Bloom?

Sorry for the confusion. When I read your post it sounded like you had adjusted the mechanical linkage to balance the vacuum at idle and not the air screws (since you said you couldn't reach a balanced condition using only the air screws).

But as Vabrzn says above, you can get back to square 1 by following that procedure:

Close them all down fully, adjust linkage for balance at or near idle, then open the air screws all 1.5 turns, then finally readjust air screws for perfect balance.

 
Well, I can attest to the '4K rpm smoothing' - did my TBS per the Warchild/factory method at 24k miles last night. Also did my plugs, which had 8k miles on them. Based on the degree of difficulty in removing the retaining clip vacuum nipples, and the fact it was 50mm of Hg off between #1 and #3 cylinder, and the fact the bike had only 7800 miles on it when I bought it, it's safe to say this adjustment had never been done.

Having never done this on any vehicle before, and having not read any other posts or other material on the subject, I had no preconcieved notion as to what the results where going to be. I was hoping for more power or better throttle response......didn't really get either of those.........

First thing I said to myself this morning when I hit cruising speed (~ 75mph, 4200 rpm or so) was "wow, that's a lot less vibration at cruise".

Mind you, I had never read any TBS threads, and had no pre-knowledge of that the results would be or might be based on prior testimonials.

Based on that, I think there is merit to the folks who state that they are able to improve NVH based on the throttle body sync.

And the Morgan Carbtune proved to be a great product, easy to use. Outstanding investment for the do-it-yourselfer. Now I can use it to sync the Webers on my 71 TR-6 (car not bike)...triple sidedraught DCOE 40s....

Beast

 
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Question 2, I setup the carbtune as per the manual. It said to install the restrictors att least 90 cm away from the gauge given 1m hoses. I installed it at 91 cm away but still find the readings fluctuating quite a bit.


When I first got my Carbtune, I remember thinking I must have totally screwed up the in-line restrictors because the gauge would NOT settle. After guesstimating how far stuff was bouncing for the next 4 or 5 synchs, I looked over the Carbtune manual (Turning in my 'man-card' now for reading the instructions - wife already had me nuts anyhow).

Nearly the first thing it says in the manual is to adjust your idle speed up just enough so there are no 'hiccups' while idling. Now I synch after increasing the standard 1050 RPM idle up to between 1100 and 1200 - Smooths the bounce out a lot. MUCH less guesstimating how far stuff is bouncing = much faster, easier synch. Remember to rev the motor a couple times between adjustments.

 
Well, I can attest to the '4K rpm smoothing' - did my TBS per the Warchild/factory method at 24k miles last night. Also did my plugs, which had 8k miles on them. Based on the degree of difficulty in removing the retaining clip vacuum nipples, and the fact it was 50mm of Hg off between #1 and #3 cylinder, and the fact the bike had only 7800 miles on it when I bought it, it's safe to say this adjustment had never been done.
Having never done this on any vehicle before, and having not read any other posts or other material on the subject, I had no preconcieved notion as to what the results where going to be. I was hoping for more power or better throttle response......didn't really get either of those.........

First thing I said to myself this morning when I hit cruising speed (~ 75mph, 4200 rpm or so) was "wow, that's a lot less vibration at cruise".

Mind you, I had never read any TBS threads, and had no pre-knowledge of that the results would be or might be based on prior testimonials.

Based on that, I think there is merit to the folks who state that they are able to improve NVH based on the throttle body sync.

And the Morgan Carbtune proved to be a great product, easy to use. Outstanding investment for the do-it-yourselfer. Now I can use it to sync the Webers on my 71 TR-6 (car not bike)...triple sidedraught DCOE 40s....

Beast
Can't find a thread for this. any suggestion to point me in the right direction.

Dave

 
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