Home made carb sync tool....Best fluid

[The Mighty Gryphon]

Nice job, Bizz!  Didn't think it was possible to do all the throttle bodies at the same time.  Figgered that my feeble brain wouldn't be able to control the flow through three or four bottles.   With one on each throttle body there is no doubt that everything is perfect.

[bizzaro]

Well it was you that led me in the right direction. Soon I will have them in a holding case similar to yours.  I was set to go with a two bottle rig like yours, but figured, what the hell.  Do them all at the same time. No hassle starting,  stopping,  and switching tubes about. (though I still think it would be simpler)  And the glass makes all the difference as well.  Thanks for all your input. 

[Motorhobo]

I'm drinking Honest Tea and peeing like a racehorse just to free up  the bottles now.

Before I go with the bottle setup instead of the tubing setup, the only drawback about the bottles I can think of is the volume of liquid and ability to read fine increments of change. I watched a video of the tubing setup and it appeared like the liquid wasn't really being displaced that much in the tubing by volume. The small volume of change was registered in a big way by virtue of the fact that the tubing is so narrow.

So you were able to get the levels equal and are comfortable with the equalness even with that comparatively large volume? I like the bottle setup because it seems easier to assemble and store -- all I need to do is drink some green tea for a couple days, pull out the tubing, tees and stoppers and go to town.

[TX brick]

So you were able to get the levels equal and are comfortable with the equalness even with that comparatively large volume? 

You don't have to get the levels the same. You only need to stabilize the levels(no liquid transfer).

[bizzaro]

Hobo,
Yes, they did even up, but that is just me being so anal.  I mean if you adjust one of the bodies so it is sucking then you will have to back it off eventually so it stops sucking!  Get it?   And I found that not watching the levels, but watching  which way the fluid was flowing in the  tubes was much better and faster.  You can really dial it in that way so that the fluid is not moving. It took a bit to get a feel for adjusting it.  I will use the loop on the outside bottles and  see if that makes it quicker and easier.  Then test it against the no loop set up to see if the readings remain the same?

 The most expensive single part in the set up.........................................THE EFFIN FOOD COLORING!!!! oh and the Nantucket Nectars a close second) The food coloring in the cabinet at home was dried up so I had to buy a $3.59 bottle of food coloring! WTF :musicboohoo: Also there was a big discrepancy in tubing prices. Quarter inch O. D. tubing, (inside diameter is perfect for a tight fit on the throttle body) was  $ .89 @ Aubuchon a foot and $.13 a foot at a local  Best Buy :yow Go figure? I used 3/8th inch O. D. tubing for the submerged tubing. Mostly because the 1/4 O. D. tubing fit into it nice and snug, no fittings needed as for the first set up that failed.  Freeze your stoppers before drilling. It helps for the first hole. but it is thawed by the time you drill the 2nd one.  I still think it helps.

Good Luck and any questions or comments much appreciated.

[szabgab]

Bizz,  this is the balancer I use for my bikes.  Two Snapple bottles, use glass because the vacuum will collapse most plastic bottles.  Two corks, I used rubber lab stoppers, but cork will work.  Two 1ft pieces of brass tube from the hardware store or hobby shop, and a vacuum line tee from the auto parts place.

Isopropyl alcohol with some red food coloring makes it easy to see the levels.  Low viscosity and weight make for the most sensitive instrument.  Use about 3/4 of one bottle divided between the two.  That way it can't get in the engine.

With the engine warm, adjust the air screws for 1 1/2 turns from lightly seated.  Balance is when the level in the two bottles is not changing.  Doesn't matter what the levels are or that they aren't the same as long as they are steady and not changing.

Don't pay any attention to the frame the bottles are in, it is the result of a fit of boredom meeting up with some scrap wood last winter.   It does help keep them from tipping over when I am using the balancer.

Hi, sorry to resurrect such an old thread... Gryph, I am just about to build this thing, as I have everything in store already. I do not have the T section, so I am planning to plug the vaccum line, or is that necessary? Would it better to have the t section in place or it does not make a huge difference one way or the other?

Thank you

[K1300S]

i realize that making your own stuff is fun, but....sometimes just buying the right tool is so much easier, simpler, more accurate and not really that much more expensive....if any.

https://www.carbtune.com/

[Filmcamera]

I have the carbtune pro as above. One tip I picked up was to hang it upside down, ie with the mercury at the top, that seems to make it easier to get a good reading and balance them properly.

[The Mighty Gryphon]

Hi, sorry to resurrect such an old thread... Gryph, I am just about to build this thing, as I have everything in store already. I do not have the T section, so I am planning to plug the vaccum line, or is that necessary? Would it better to have the t section in place or it does not make a huge difference one way or the other?

Thank you

No need to block the vacuum line to the fuel pressure regulator.  It's only real purpose is change the fuel pressure when decelerating with a closed throttle.  I'm guessing that it's to help reduce backfiring.

The Carbtune device is nice, but even with three bikes, I can't justify the cost vs. the two bottle unit I made.  Sure, my rig takes a little longer to get the job done, but I doubt the Carbtune gets noticeably better results.  I can get my throttle bodies close enough that even after a minute there is no movement of fluid between the bottles. 

[K1300S]

use a carbtune once, and you will see that the cheap price is absolutely justifable.   I can probably do two bikes worth of balance in the time it takes to fill bottles....;-)  no mess, no set up time, stores in a nice pouch, toss in the tool box. can do three or four cyl at once.



by the time you are done putting the Kool aid away, i will be on my second IPA...;-)

[szabgab]

use a carbtune once, and you will see that the cheap price is absolutely justifable.   I can probably do two bikes worth of balance in the time it takes to fill bottles....;-)  no mess, no set up time, stores in a nice pouch, toss in the tool box. can do three or four cyl at once.



by the time you are done putting the Kool aid away, i will be on my second IPA...;-)

Although I am sure, a tool made for a specific purpose is a nice thing to have, but I already have way too many toys, at least according to the significant other. The bottle setup cost me about 5-10 USD and I could drink two bottles of posh juice, I would never consider buying otherwise.  Now I will need to see, if I can get the bodies properly synced, as being lousy is my forte... But the setup looks to be idiot-proof :)

[The Mighty Gryphon]

$100 with shipping vs $10.  I only use mine a couple times a year, mostly to check balance since it doesn't change much on my bikes.  Once it's built, it takes no set up other than to connect to the vacuum ports on the throttle bodies. 

Adjusting is straightforward, screwing the adjuster screw IN raises the level in the bottle connected to that throttle body, backing it OUT makes the level go DOWN.  When the fluid level in the bottles stops moving the vacuum is equal in both throttle bodies.  Let it sit for a minute while the engine idles to see if the level changes over a period of time.  Very small tweaks when it's close lets you zero in on the best setting. 

With only two bottles, I adjust #3 cylinder on a K75 or #4 on a K100 to 1 1/2 turns from lightly bottomed.  Then I attach the bottles and set the other throttle bodies to the one I set.  For a double check, I'll connect the bottles between the #1 and #2 throttle bodies.  It only takes me about 15-20 minutes start to finish to get my throttle body settings to within 1% of the perfect setting.     

That it takes 15-20 minutes including the time to warm up the engine doesn't bother me at all.  It's the last thing I do after a tune up including valve clearance and it gives me a nice feeling to see the results of the work I've just done.

[DavidATL]

I am interested in looking into syncing the throttle bodies using exhaust temperature. So as to NOT thread jack, I started a new discussion " throttle body syncing by exhaust temp" in the workshop to see if others want to chime in.

[johnny]

greetings...

it has been suggested for repeatable dependability that denatured feck be used as manomater agent...

j o

[DavidATL]

greetings...

it has been suggested for repeatable dependability that denatured feck be used as manomater agent...

j o

That's some kinda of BS. May not B, but definitely S.

jk

[johnny]

greetings...

have you tried denatured feck...

j o

[szabgab]

Adjusting is straightforward, screwing the adjuster screw IN raises the level in the bottle connected to that throttle body, backing it OUT makes the level go DOWN.  When the fluid level in the bottles stops moving the vacuum is equal in both throttle bodies.  Let it sit for a minute while the engine idles to see if the level changes over a period of time.  Very small tweaks when it's close lets you zero in on the best setting. 

With only two bottles, I adjust #3 cylinder on a K75 or #4 on a K100 to 1 1/2 turns from lightly bottomed.  Then I attach the bottles and set the other throttle bodies to the one I set.  For a double check, I'll connect the bottles between the #1 and #2 throttle bodies.  It only takes me about 15-20 minutes start to finish to get my throttle body settings to within 1% of the perfect setting.     

Gryphon, this is great. I have read elsewhere, that one should start with number 1, as that adjusts the idle speed also, but that sounds contradictory to everything else I have read on this topic, including your description above. Although for some reason I can not lower my idle speed below 1200-1300RPM, so probably my adjustments are way off, also TPS seems to be preventing the throttle body linkage to lower itself any further, than it is at the moment (even if I back out the idle stop screw all the way out). I did remove the TPS screws in order to angle the whole assembly, but it seems to me, it is all bottomed out on it's adjustment, so something is not completely right there either

[K1300S]

Gryphon, this is great. I have read elsewhere, that one should start with number 1, as that adjusts the idle speed also, but that sounds contradictory to everything else I have read on this topic, including your description above. Although for some reason I can not lower my idle speed below 1200-1300RPM, so probably my adjustments are way off, also TPS seems to be preventing the throttle body linkage to lower itself any further, than it is at the moment (even if I back out the idle stop screw all the way out). I did remove the TPS screws in order to angle the whole assembly, but it seems to me, it is all bottomed out on it's adjustment, so something is not completely right there either

check everywhere for a vacuum leak.  propane torch(unlit!) works well for this.

[The Mighty Gryphon]

I never heard about starting with #1 when adjusting the throttle body vacuum balance.  That sounds like something from the procedure for setting the butterflies.  Since that involves the "forbidden blue screws", I've never done that. 

The high idle rpm needs to be reduced.  If the throttle butterflies are open it will be impossible to properly balance the throttle bodies.  Have the forbidden blue screws been molested?  If so, you have a major problem and probably have to replace them.

If the blue screws are okay, check for the throttle linkage hanging up on the clamps that hold the airducts on the throttle bodies.  If that's okay, set the air screws for 1 1/2 turn out from lightly bottomed, remove the throttle position switch, and start the engine. That should get you close to 900-1000rpm.  It's also possible that the "choke" mechanism is holding the throttles slightly open.  Check the operation of the choke, try disconnecting the cable at the handlebars, does that lower the idle speed?

Unless the throttle linkage is damaged, these are the main things that will cause a smooth high idle speed.

[szabgab]

I never heard about starting with #1 when adjusting the throttle body vacuum balance. 
Unless the throttle linkage is damaged, these are the main things that will cause a smooth high idle speed.

I finally managed to find some time to balance the throttle bodies today, as the mini-lab (as the wife called my setup) was all set up. The engine became really smooth after this across the whole range, so it was very much worth doing it. I am not sure, if the forbidden screws were touched or no before, as blue paint is present, but the screws are not smothered in it just a lick on the sides. I will include some pics for reference.

First I have done it your way, third body first and so on, but the idle speed remained high, and I had to adjust the first body a lot in the region of three turns out, or so. So I skipped it all and started afresh, this time having the first body out by the 1.5 turns and adjusting the others accordingly, mostly closing them a bit more in order to gain an equal vacuum. This made the idle so low, I had to actually raise the linkage stop screw, otherwise the bike started to stutter. Obviously something is not right if one the bodies need such a different setting, as the other two, but the bike is ever so smooth now, tach is not jumping up and down, as it used to, acceleration etc is better so all in all I am a happy camper. I will redo this test again once the weather clevers up a bit, as doing something like this in -5C is not fun, also the engine will never get as warm, as it could plus the fluid is more dense in around zero centigrade... Also replaced the oil, so the bike starts immediately, even stone cold so I am happy on that front too....

[The Mighty Gryphon]

Good work!  Sounds like you've got it pretty close now.  Should get you through to Spring when you can fuss with it a bit more.

I've had that thing with the screw on one cylinder needing to be backed out a lot more than the others.  Have you done the valve clearances lately?  I suspect that may have some bearing on the balance.  That's why you should always do the throttle bodies last.

It looks like the blue paint is undisturbed.  That's good news.

[szabgab]

Good work!  Sounds like you've got it pretty close now.  Should get you through to Spring when you can fuss with it a bit more.

I've had that thing with the screw on one cylinder needing to be backed out a lot more than the others.  Have you done the valve clearances lately?  I suspect that may have some bearing on the balance.  That's why you should always do the throttle bodies last.

It looks like the blue paint is undisturbed.  That's good news.

Well, my valve clearances will have to be sorted soon, as they are 0.12, 0.12,  0.15 on the intake side and 0.27, 0.25, 0.25 on the exhaust but that will be the story of the big Spring shake-up :) As long, as I have the mini-lab somewhere safe, I can resync everything in a very short time afterwards..

BTW I was worried that the bottles contain a relatively large amount of fluid, hence making it harder to see miniscule movement, but if you leave it on for a minute or two, even the slightest difference manifests itself. The final adjustments were probably 1/100th of a half-turn, so I guess the homebrewn manometer is a very precise instrument indeed 

[The Mighty Gryphon]

Sounds like you have the hang of it.  Spend the money you saved on a dinner for your wife.

Another way to magnify small level changes is to put a strip of tape with some marks on it diagonally on the bottle.  A 30 degree angle from horizontal works well.  It will magnify level changes x2.

[Soggz]

NOT home made,......... but I like it !!!

thats what I use. Amazon.£35.00

[szabgab]

thats what I use. Amazon.£35.00

Do you mean the silicone boobs or the measurement tool?  :)

On a serious note,  do these need any dampening? Aren't the needles jumping up and down too much without restriction?