Carb Syncing

Just found this while browsing

http://www.powerchutes.com/manometer.asp

What do you think, anyone tried it, do you think its worth building.

 

Its similar to Ricks manometer

 

I made something similar from 20' of clear 1/4" tubing, a 3' long X 5" wide board, and a couple of plastic tees. It works very well.

I cut the tubing in half and formed 2 big U 's. I then cut each of them in half in the middle and put the cut ends on the end of each tee. I used a short piece of tubing to connect the 2 U"s together and stapled the 4 tubings to the board, leaving about 2' hanging back over.

I connected the loose ends to some 4' pieces of vacuum line. I repair dental equipment for a living, so I have a large assortment of barb fittings. I put a 1/8" X 1/16" barb fitting inside the end of each clear tube. It swelled the clear tubing enough to make it a snug fit inside the vacuum tubing and also serves as a restricter. I filled the tubing U"s with 2 cycle oil.

Hook-up the other end of the vacuum line to the intake manifold ports. You now have a re-usable sync. gauge that is fairly sensitive. If you suck up the 2 cycle oil into the engine, you will not harm it.

You can also view all 4 carbs at once. You will see how changing one affects the others. With a little patience, you can get your carb well balanced. Follow up with Colortuning and you will have a smooth idling and accelerating bike. Make sure to block off the YICS ports if your bike is so equiped.

Happy tuning,
Mike

 

Please pardon the potential silliness of this question but will this take the place of the $100 YICS tool from a shop? If so, count me in....lol

 

It looks like it will only do a Twin-Cylinder.

 

The one I described will do a 4 cylinder engine, You still need the YICS blanking tool. You can either make one, or buy one from Chacal like I did. If I recall, it was $37, and works very well.

 

The tool that chacal sells is a very nice tool. Mine works great. Just what I needed to set my carbs up right. I use a 4 vacuum gauge sync tool I got off of e-bay. It had the restrictors (Valves like for an aquarium air pump) and all the adaptors to fit other bikes. That was about $60.00. The water type I hear works just as good.

 

Just remember....you don't "synch carbs", you "synch an engine"----you are trying to get the power output of each cylinder "in synch" with each other (as measured via the vacuum draw of each cylinder).....which is why the first step in Yamaha manual concerning "carb synch" is to make sure that the valve clearances are within specification......

Once your valve clearances are okay, then you can adjust the power output (by measuring the vacuum pull) of each cylinder and adjust the power output of each cylinder by adjusting the air-fuel mixture draw through each carb,, in order to bring the higher-output cylinders DOWN in power output to the level of the lower-output cylinder.

Given that the process of "synch" is, in actuality, a method of REDUCING the power output of 3 out of 4 cylinders, you want to take all precautions, and steps necessary to make sure that your lowest-output cylinder is outputting as much power as is possible...then you won't have to reduce the total engine output of those three other cylinders any more than necessary:

a) valve clearances, and
b) carb system operation (internal cleanliness, no vacuum leaks at the intakes, throttle seals, or airbox intake boots, and proper vacuum diaphram operation "clunk").

 

I made one of those homemade synchronizers for my V-twin and it worked perfect.
Then I figured a way to synch my in-line four with it also. It never did idle just right and I figured it should have better pick-up thru the gears.
I just matched no. 1 cylinder with no. 2. Then I matched no. 3 and no. 4 to each other. Then I matched the right bank to the left by matching no.2 and no. 3.
Now it idles like it never did before and runs like a cat-on-fire thru the gears! For a few bucks it's priceless. And to think I was actually considering wasting money on those expensive gauges to synch the carbs.

 

With the build price being so cheap i was thinking of making 2 then you could sync it all at the same time, the XJ seems pretty well sorted and will idle reliably as low as 800 rpm, my newly aquired GPZ600R needs a bit of syncing as the idles not the best but it just flies when you open it up and the handling is a revalation compared to the XJ.

 

Two won't work. Carbs 1 and 2 are synced together, 3 and 4 are synced together then 3 and 2. Since this manometer only measures difference in pressure between 2 carbs there is no way to connect 2 of them to sync all 4 carbs.

I suppose you could use 3 of them with some Y type fittings but I'm not sure how well that would work.

I have one of these and it was a pain since my sync was way off. It fragments the oil in the tube easily and then you have to get the bubbles back out. I converted to a vacuum gage.

 

I made one of these:

Bottle Sync Tool

I used ATF fluid first. but it was too thick, so i used water the second time, muuuuch better, instant indication of which side was pulling harder. It's VERY sensitive, i could turn the screw a millimeter and throw it off.

How many of you guys have made/used these?

 

The bottom line is getting all four Carbs to be precisely adjusted so that the Manifold Vacuum is the same on each one. Period.

It doesn't require elaborate measures or yards of clear vinyl tuning.
One Vacuum Gauge, a few feet of vacuum hose and a handful of golf tees will do the trick.

Just as accurately as any store-bought quad manometer or jury-rigged Rube Goldberg contraption you can dream-up!

 

Perfect timing.
I just got my bike started today (its been sitting since 2005). Had a little trouble with the carbs (hello)! Jerry rigged a tank (wal-mart has a funnel with a lid and attached shut off valve $3.88 a little extra tubing and ta da mechanic's tank) She runs but does not want to start w/o starter fluid. But she runs fine after that. Suggestion?

I guess the next step would be to synch the carbs?
So let's say that you are using just one vacuum gauge (found one at Harbor Freight $12) where would you begin and what would be the setting?

 

Easy ... Just hop in RickCoMatic's Time Machine, and come back with me, to the time before Carb Sticks; when you had to "Match-up and Sync the whole rack ... with ONE Vacuum Gauge!

The Old School Method
Single Vacuum Gauge Synchronizing of Carburetors
by: Rick Massey
Special to XJBikes.com
All rights reserved.

First, you need one vacuum gauge. (There's none better than the one sold at Sears for $19.95) and your home-made YICS tool.

A couple of Electric Fans to keep the Old XJ from overheating while you do the tuning-up. Two. Aimed at the Engine. High speed for Max cooling!

You need some vacuum line. Get ten or twelve feet. You'll be making-up lines to run from each carb out to the side of the bike where you'll hook-up the Vacuum Gauge.

You need a few small, hollow, plastic-barrel vacuum line connections. (Those little things you use to plug one vacuum line into another.)

One small, inline fuel filter; with ends that will fit the hose.

One red plastic spray tube ... like the one taped to a can of carb cleaner.

Four regular Golf Tees. (Just steal 'em from your dad's golf bag)

5-minute epoxy.

Masking tape and a "Sharpie"

OK kids ... Let's ROCK!

Prep:
Fabrication of the "Vacuum Restriction Valve." (Absolutely necessary)

Take the skinny red tube and run it through one of the hollow, plastic hose connectors.
Seal that hollow connector with epoxy; leaving a length of the red tube extended from each end.
(This fabricated little-metering device will be the all-important "Vacuum Pressure Restrictor" that will allow you to read the vacuum gauge without the extremely WILD fluctuations on the meter you'd get if you tried to get a vacuum reading without it.)

When the epoxy hardens; cut-off the extraneous ends of the red tube -- flush.

Using a short length of vac line ... attach the restrictor to one end of the medium-sized fuel filter.

(Now you have a restrictor attached to the fuel filter. You just made what you NEED to get the needle on the vacuum gauge "Quieted-down" enough to get an accurate reading without the meter being so wildly fluctuating as to be useless. You have Baffled-Restricted-Regulation and this softens the harsh, impossible-to-read fluctuation, the indicator would have, without it.)

Hook-up and Sync:

The rest is by the book.
YICS tool inserted.
Four Vacuum lines run from the Carb Intakes over to where it will be convenient for you to connect these four lines up to Vacuum Gauge ... each marked with a little tape label for one through four. Stick the golf tees in the ends of these lines ... and get ready to sync the carbs.

Attach your "Old School - Baffled Restrictor" to the vacuum line coming from Number - 3 with the red tubed restricted end plugged into the vac line coming off the engine.

Plug the Vacuum Gauge into the Fuel Filter end. You're officially restricted and baffled for testing ...

So, let's do it!

Run the bike and get the vacuum reading of Number 3 (Three) ... to check for good vacuum on three and to observe how the needle of the gauge is still going to MODERATELY "Vibrate" as it measures engine vacuum.

Sneak the rev's up to 14 > 16-hundred rpm's and the fluctuation will become rapid enough for you to read the vacuum that the hole is pulling.

Mark the gauge face with a short strip of masking tape and mark the tape with a check-mark. Don't let the tape strips block you from seeing the vacuum gauge needle during the sync.

Authors Note:
It's a good idea to practice pulling a golf tee out and covering the hose with your thumb. This will keep the engine from stumbling and possibly stalling.

Checks and adjustments:

Read the Vacuum being pulled by Number 2. Mark maximum vacuum drawn by 2 with line of tape.

Get your magic fingers ready to do the "Carb-Shuffle!"

Pull-out the baffle and block the vacuum with your thumb until you can insert the golf tee you have ready between your lips or behind your ear.

Measure the vacuum being drawn by Number 1. If the max vacuum being drawn by Number 1 is NOT the same as you have MARKED for Number 2 --ADJUST the SYNC SCREW on Number 1 ... until the Vacuum drawn by ONE is the SAME as the Vacuum drawn by TWO!

Two down ... two to go! But, here's where it gets tricky.

Plug-in to Number 4. Set the Vacuum drawn by Number 4 -- to -- the BASE Vacuum you measured for Number 3. (Actually check 3 again ... adjust 4 to match 3 -- because 3 is the Base Vacuum Port, has NO sync screw adjustment, and usually has the petcock vacuum hose connected to it.)

At this point you start TWEAKING. From here until the rack's in-sync ... it's all down hill!

The engine should be sounding pretty darn good; right about here. But, we need to finish it off!

Just hook-up to Number 2, now ... and bring the vacuum being drawn on Number 2 -- UP or DOWN to match the value of Number 3.

They'll be no need to adjust Number 1. Number 1 is connected to Number 2 and goes right along for the ride when you sync Number 2 to Number 3 ... and you ...

HEAR the results of synchronizing all four of your carbs with only one vacuum gauge.
Let what I have outlined, here, be your guide ... but, don't be afraid to get creative with where to have the golf tees ready to pop-in the lines!

When you wrap-it-up ... the One - through - Four ... Final Measurement should be all right on the same value -- right across the board.
Yes? DONE!
No? Tweak until you nail it!

Can you believe that we used to have to do it this way? Compared to the MotionPro Carb Sticks -- It's like being in Bedrock ... spending a little time with Fred and Barney doin' a little Stone Age Tweaking'!

 

These are the Easy-Way-Out method of synching........not the cheapest, but certainly the easiest-to-use and the best synch gauge out there. NOTE: be wary of using fluid-filled synch sticks, the reports from the field on their performance are less-than-encoraging!!



j2) Aftermarket Morgan CARBTUNE PRO 4-COLUMN SYNCH GAUGE TOOL.......brand new, no display box, includes all accessories and instructions. This is the one that professionals use and recommend, and is superior in design, ease of use, and accuracy versus vacuum gauges and all other versions, whether fluid-filled or otherwise. Uses damped stainless steel sliding dowel rods instead of mercury or the "blue mystery fluid", giving accurate, safe, and easy-to-read measurements. More expensive than other synch tools and worth it. Use it even once and you'll wonder how you lived without it.

NOTE: this tool is used on all XJ engines, regardless of whether it is a "YICS" engine or not.

Also, please note! you can sometimes find these same sticks selling at a discount at various places, but most of these places are offering a much older, now-discontinued Carbtune II version, rather than the latest, much-improved Carbtune PRO version that is offered here. The PRO version is much more durable, accurate, and easier to clean and service than the older version.

HCP96Q Aftermarket Morgan CARBTUNE PRO 4-COLUMN SYNCH GAUGE TOOL.
$ 114.00


j3) Aftermarket Carbtune Pro STORAGE AND TRANSPORT CASE for the above carbtune pro synch stick......a heavy duty, nicely made zippered and clasp-closure storage case to hold the gauge and all the accessories neatly and safely. You REALLY want to have this to safely store and transport the (somewhat fragile) synch gauges!

HCP1287 Aftermarket Carbtune Pro STORAGE AND TRANSPORT CASE.
$ 19.00

 

thanks Len, but I'm reaching my $500 limit. Wifey said sure to the free bike, but on a limited budget. I guess I'll try the manometer method.