Cheap Carb Sync

[tiny84]

ok i'm looking to do a carb sync on my scoot and just cant afford the tool or having the dealership do the work. (Have you seen the price of gas I comute 2 hours everyday for work)

 

so anyway I found this great DIY carb sync tool seems more accurate then the the tube and oil method. great walkthrough on how to make your own.

 

http://faq.ninja250.org/index.php/Is_there_a_carb_sync_tool%3F

[KiteSquid]

Good idea, but how do you use it on a four cylinder bike like the RSV???????

[scotty]

I used the oil method, I just built it to accept 4 carbs.

http://www.delusional-mechanic.com/

It seems to have worked reasonably well.

Scotty

[tiny84]

I was under the impression I could just sync carbs 2, 3, and 4 to the 1st carb. Hook up one line to the first carb then the the #2 carb sync then hook to carbs 1 and 3 sync and finnaly hook to carbs 1 and 4. if all carbs are matched to #1 then they should all be at the same setting thus being synced... if i'm wrong someone please let me know so I dont waste my day off doing this.

 

 

you could i guess addapt this to fit a V4 by adding 2 more bottles and lines run to each vacume port then a set of tubes run between each bottle to the others which ever carb had more suction would collect the water in that bottle. and no extra fluids end up going into your motor.

[Squeeze]

you adjust #2 to #1, then #3 to #4, then both right to both left Carbs.

 

Speaking in Screws, that's left Screw, then right rear and finally right front Screw.

[Dano]

you adjust #2 to #1, then #3 to #4, then both right to both left Carbs.

 

Speaking in Screws, that's left Screw, then right rear and finally right front Screw.

 

 

Whhooops, thats #1 to #2 carb, then yur other side (#2 carb is non-adjustable).

Just had to mess with you Squeeze!

 

Dan

[Squeeze]

Whhooops, thats #1 to #2 carb, then yur other side (#2 carb is non-adjustable).

Just had to mess with you Squeeze!

 

Dan

 

You may be right Dan, you got me !

 

I better should stop messing with that EFI and renew my Particulars about the Carbs.

[Guest Moby]

I just sinced my 84VR and #2 carb is the dedicated carb (non adjustible).

[BigBoyinMS]

I just did the same thing today... made a bottle manometer and synced. Water worked just fine, too.

FYI, for anyone that doesn't already know... the service manual definately has the wrong info on which screws adjust which carbs. I knew it but misread the correct info so it took me a bit longer than it should have.

Here is a pic (if I did it right) of the tool I made.

[igya]

ok i'm looking to do a carb sync on my scoot and just cant afford the tool or having the dealership do the work. (Have you seen the price of gas I comute 2 hours everyday for work)

 

so anyway I found this great DIY carb sync tool seems more accurate then the the tube and oil method. great walkthrough on how to make your own.

 

http://faq.ninja250.org/index.php/Is_there_a_carb_sync_tool%3F

 

Just my opinion, but my experience with adjusting 4 bangers is having separate gauges (on a common manifold) for each carb is best. Because, you can adjust #1 and then after #2 is adjusted, #1 gives a different reading. Get #1 & #2 sinced, then after #3 is done, 1 & 2 are usually higher than what you originally had, and so on. Tach is fair, Vacuum is good, mercury is best. Hey! Just an opinion (and we ALL know what an opinion is like, right?)

[KiteSquid]

mercury is best.

 

Where can I buy a four tube Mercury manometer??????

[MiCarl]

The bottles make it too complicated. The fluid level in each bottle needs to be exactly the same, the connecting tube needs to be full.

 

Easier to just use clear tubing bent into a U shape. If you want to hook up all 4 carbs you need two tees to make a 4 legged U.

 

ATF makes a nice fluid because it is easy to see.

[BigBoyinMS]

The bottles make it too complicated. The fluid level in each bottle needs to be exactly the same, the connecting tube needs to be full.

 

Easier to just use clear tubing bent into a U shape. If you want to hook up all 4 carbs you need two tees to make a 4 legged U.

 

ATF makes a nice fluid because it is easy to see.

 

I have to disagree with you. The liquid in the bottles just needs to be close, not exact to the Nth amount and the connecting tube doesn't even need to be full. All we are doing is equalizing the pressure/vacuum between the two and the carbs are synced. But I'll mainly take the safety factor of no chance of sucking a few oz's of mercury into my carbs for the tiny amount of extra work and time that comes with attaching and removing the tubes 3 times. Or even 6 times if you double check yourself. And I'll use the $100 I save from not buying the merc tubes for gas or accessories.

Edited August 26, 2008 by BigBoyinMS

[JPS]

I've tried both of the homemade setups (two bottles with oil and the 4tube manometer with Transmission fluid) and I wasn't real pleased with either. The two bottle setup was difficult to detect fluid movement in. I found I was straining to see small air bubbles moving one way or another, and that made it difficult. Trying to gauge changes in level in an unmarked bottle was impossible, so bubble movement seemed the only way to determine what was happening.

 

My 4 tube transmission fluid filled manometer was extremely sensitive, and I guess my carbs where off a fair bit, so the fluid on the left bank quickly started heading quickly for the carbs. I had to twiddle the balance between left and right sides to get to where I could start to work on the balance between 1 and 2 cylinders. Had to continously stop as air bubbles got into the system, and the system was pulsing. I modified the system with restrictors, which helped, but I found that the system kept trying to pump the Transmission fluid into one bank or the other, and I had to shut off the motor every time this started happening to let the fluid settle and be ready with an adjustment as soon as the motor started.

 

I eventually got to where I feel the carbs are in pretty good balance, but because of the bubbles in the fluid and the drawing in of the fluid into the engine, forcing me to shut down so many times and wait a minute or two, the process ended up taking a couple of hours. Maybe it'll go better next time, as hopefully the sync will be closer, but the Transmission fluid filled manometer is almost too sensitive, I think. I've attached a photo of my setup. I had to drain some ATF fluid out to lower the start level, as it gave me more time to twiddle adjuster screws before the fluid got sucked into the engine.

 

I'd like to hear how others got along with their home made setups. How did it go for you?

 

Cheers,

Joe in Sunny Chandler AZ.

[V7Goose]

There are people here who have said they are perfectly happy with a home made two-unit manometer. I'm glad they are, but I personally advise heavily against it.

 

Technically, you SHOULD be able to identify the reference carb and sync each other carb to that with just a twin unit, but in reality, it just ain't so. I have done a LOT of Royal Stars, and other 4-cyl engines, and the interaction between carbs from changing any setting is just way too much. Even when using a 4-gauge set, I am going back and forth numerous times before all of them are equal. If I was having to disconnect/reconnect a gauge to check all four carbs after touching each screw, I doubt the job wold EVER be done correctly.

 

To anyone who thinks they can do it and like it, my hat is off to you, but I have to advise against it for anyone else. ESPECIALLY for someone who has never tried it before! Get any 4-tube or 4-gauge manometer and do it right. You can buy both mercury and mechanical gauges from JC Whitney (or at least you could last time I checked).

Goose

[paperboy]

Has anybody had any experience with CarbMate from tecmate.com. One of the cycle mags gave it a great review. It's all digital. $109.90 plus extra for multi cylinder adapters [3+4 cylinder ]. The writer said it's almost foolproof.

[KiteSquid]

Ummmmmmmmm the 4 channel VacuumMate starts at $499.00 or you can get the $579 model with the internal battery.

 

My mercury carb sticks were about $80 and do not go out of calibration like any electronic or mechanical set up will do over it's life.

 

 

Yes I have to be careful to NOT spill the mercury.

 

 

I properly built DIY four tube ATF monomers looks like a close second...

[djh3]

So on the homemade job you have the 4 tubes with a fluid. I was actually thinking of using a pice of PVC at the bottom and putting 4 ports in it, same idea as the T fittings I supose. Anyways when all 4 carbs are hooked up, what keeps the engine from just sucking the fluid straight into the vacuum port? Or is it if you balance out the vacuum between cyl even the pressure is even so no one cyl can draw the fluid?