Carburetor Syncronisers.

[MiCarl]

...The Motion Pro SyncPro needs to be calibrated, and shows a procedure in the instructions. Why is that? If it's simply 4 tubes with liquid from a single source, how could that go out of calibration? ...

 

Because the 4 tubes do not go to a single source. Each tube has it's own chamber of liquid.

 

What the gauge is measuring is the pressure relative to the air bubble above the liquid. The adjustment screws change the pressures on the air bubbles. Because the bubbles are of varying sizes the accuracy changes at different levels of vacuum - requiring a calibration for each use.

 

I use the Motion Pro SyncPro in my shop. While calibrating it requires and extra step, it has several advantages:

 

1) Since each chamber is isolated there is much less risk of drawing the fluid out of the device.

 

2) Because of reason 1 they can use a very low density liquid (compared to mercury) which results in a very sensitive gauge.

 

The really big drawback to the SyncPro is it doesn't give a pressure reading (just comparisons). If you use a mechanical gauge or mercury stick and see all your cylinders are pulling 2 CM HG you know you have cylinder(s) that aren't firing. That's not so obvious with the SyncPro.

 

I used to use the mechanical gauge set from J.C. Whitney. Over time I noticed that the gauges were not accurate - they didn't all end up back at 0. I was recalibrating them often to make sure I got good results. The other problem with this set is it seemed I needed to readjust the vacuum restrictors at every use.

 

So on balance I think with the SyncPro my set up time isn't any more than with the mechanical gauges. It's definitely much easier to read.

 

If you decide you want a SyncPro I think you'll find it cheaper in my store than anywhere else: Thunder Valley Powersports. Remember to use discount code VentureRider at checkout to save 15%

[atlm]

Thanks for sharing. I'm still not clear on a few things, though.

 

Because the bubbles are of varying sizes the accuracy changes at different levels of vacuum - requiring a calibration for each use.

 

Why aren't the bubbles all the same size? Seems like that would eliminate the need for calibration.

 

The other problem with this set is it seemed I needed to readjust the vacuum restrictors at every use.

 

I thought the vacuum restrictors just got shoved into the vacuum lines to restrict airflow to lessen the pulsing affect and smooth out the readings, and that was that. What am I missing?

[V7Goose]

OK, three more questions:

Are yours the Emgo gauges, like those being sold by Saber?

Did you do a similar test with yours as you did with the Motion Pro unit, testing their calibration across different amounts of vacuum with a hand pump? Is that part of what you refer to when you say the mechanical gauges work absolutely consistently?

Is my understanding correct that they can be calibrated?

 

Let me know. If so, I think I'm sold.

I have no idea what brand name my gauges had all those years ago when I bought them, but they look identical to the pictures in this thread.

 

Before I use any multi-vacuum set the first time, I check it by connecting all the inputs to a single manifold and draw various vacuum levels with a pump to verify accuracy and consistently repeatable values. On my gauges I repeat that test every year or so just to be sure all is as it was. In over 30 years I have only adjusted one gauge slightly two times.

 

If one or more needs to be adjusted, you pop off the front glass and pull the needle off, then replace it in the correct spot. CAUTION - do NOT try to turn the needle on the shaft instead of pulling it off - that will destroy the internal spring that connects it to the vacuum chamber!

Goose

[MiCarl]

Thanks for sharing. I'm still not clear on a few things, though.

 

 

 

Why aren't the bubbles all the same size? Seems like that would eliminate the need for calibration.

 

 

 

I thought the vacuum restrictors just got shoved into the vacuum lines to restrict airflow to lessen the pulsing affect and smooth out the readings, and that was that. What am I missing?

 

If the bubbles were all the same calibration wouldn't be necessary. That would require a lot more expensive calibration and if you dumped the fluid out (it's possible) you'd never get it right.

 

On the mechanical gauge set I have (looks just like the picture earlier in the thread) the restrictors are little valves in the lines. Seems like every time I used it I had to readjust 2 valves because either a gauge wouldn't move or was bouncing all over the place.

 

The SyncPro has little orifices that are pushed into the hoses.

[atlm]

If the bubble sizes are different, that explains why calibration for the SyncPro only works at a specific vacuum level, and gets thrown off as vacuum levels change. I'm guessing it has to be water pressure against a bubble, rather than open-topped pulling from a single source, because of the light weight of the blue liquid as compared to mercury. Either way, although I'm sure it would get the carbs close enough, there appear to be 2 choices that are more accurate for less money (no offense to any SyncPro fans, but that's just the way it appears to me at this time based on what has been shared here).

 

I wonder if the little restrictors from the SyncPro (or even a small piece of hose shoved into the larger hose) can be used in the lines for the round gauges for the best of both worlds. Anything that stays pretty much calibrated over 30 years of use is pretty super awesome.

 

Sounds like, for the round gauges, a couple of other purchases are necessary:

A 4 into 1 vacuum hose adapter for calibration (the SyncPro includes one of these, the mercury unit doesn't need one)

A tach - now available for $20!

Maybe some in line vacuum restrictors?

[MiCarl]

there appear to be 2 choices that are more accurate for less money (no offense to any SyncPro fans, but that's just the way it appears to me at this time based on what has been shared here).

 

Actually, the SyncPro has NO accuracy (there isn't even a scale on it). What is needed for a good sync is sensitivity. The SyncPro is way more sensitive than cheap gauges or mercury sticks.

 

Are the cheap gauges sensitive enough to do a good job? I think so. I've made a lot of engines purr like a sewing machine with them. I did worry that over time the cheap mechanical gauges seemed to lose their calibration, at least at 0.

[atlm]

Thanks for all the information!

 

When I mention accuracy, the only thing I'm talking about for carb sync tools is the ability of the 4 tubes, gauges, liquids, or whatever, to stay in sync with each other across the range of vacuum readings that they'll be used. The actual number reading on the gauge/tube/whatever has almost no significance, since all we're doing is making them the same, not bringing them to a value.

 

From my understanding of the SyncPro, it's calibrated at a given vacuum level. If, when you're done synchronizing, all of your carbs end up at a higher or lower vacuum level than the one you used to calibrate, your carbs are actually out of sync with each other. Close enough if you already own one? Probably. But if someone is gauge shopping, I'm totally in agreement with Goose, based on my current understanding.

 

The mercury gauges seem great, also, and are definitely a great price, but have their drawbacks which have already been pointed out by others.

[V7Goose]

 

Sounds like, for the round gauges, a couple of other purchases are necessary:

A 4 into 1 vacuum hose adapter for calibration (the SyncPro includes one of these, the mercury unit doesn't need one)

A tach - now available for $20!

Maybe some in line vacuum restrictors?

The gauges have always come with four inline valves used to provide the restriction necessary to settle the bouncing. This is a good solution because the amount of restriction you need varies depending on the frequency of the pulses (engine speed). It also lets you temporarily open a valve more to verify the line/restriction is not plugged by something and that the gauge is not stuck. The proper setting is so the needles just slightly wiggle, which lets you know all the time that the gauges are getting the proper level of vacuum. If you close them down so that all wiggling is stopped, the gauge can continue showing the vacuum in the line behind the valve even when it changes on the engine side. The plastic valves are not of the highest quality, but they do the job. I changed mine out for brass aquarium valves long ago.

 

As for making a four-line manifold, just go to the hardware store in the drip irrigation section and buy three plastic T connectors and 1 foot of plastic hose to cut up - the whole thing will probably cost you less than a buck!

 

As for long term accuracy - like I already said, mine have remained accurate. I can't say for positive that they point to the EXACT same spot at zero, 'cause I never look at them at zero - that means there is no vacuum applied; therefore, it means I am not using the gauge!!!! What I care about is that all four gauges read identical levels of vacuum at anything between about 2" and 20" of mercury, and my vacuum pump proves that this is, and always has been, true for this set.

Goose

 

Oh, no tach is necessary for the gauges any more than it is for a different vacuum tool

[Tom]

I have no idea what brand name my gauges had all those years ago when I bought them, but they look identical to the pictures in this thread.

 

Before I use any multi-vacuum set the first time, I check it by connecting all the inputs to a single manifold and draw various vacuum levels with a pump to verify accuracy and consistently repeatable values. On my gauges I repeat that test every year or so just to be sure all is as it was. In over 30 years I have only adjusted one gauge slightly two times.

 

If one or more needs to be adjusted, you pop off the front glass and pull the needle off, then replace it in the correct spot. CAUTION - do NOT try to turn the needle on the shaft instead of pulling it off - that will destroy the internal spring that connects it to the vacuum chamber!

Goose

Goose,The gauges you have I bought also with one exception..The new model you just pull the front plastic (or glass) and it has a screw you turn with a small screw driver to calibrate....sure makes it easy and Yep I like the gauges..I appreciate you being there for me to call when I get stumped at times..Thanks!

[atlm]

The round gauges being sold by JC Whitney are going for $120. The set of round Emgo gauges is being sold on eBay by Saber for about $52 shipped. There's another seller on eBay - SportingForLess - selling gauges that look the same for $60 shipped, and in their ad, they claim that they're having their gauges made for them in Taiwan because the Emgo gauges have a huge calibration issue: "Those are top quality sync gauges, specially made for us from taiwan manufacture, they are not cheap "??GO" gauges. (we used to carry "??GO" brand sync gauges, due to the quality problems, 25% of those gauges are out of calibration, we had to send them back to the distributor, we no longer carry them anymore)"

 

 

Goose, your gauges are from JC Whitney, and have served you well, but we don't know if they're from Emgo or not. Has anyone purchased and used the Emgo's or those being sold by SportingForLess? Is SportingForLess full of bologna, or are the Emgo's a cheap knock-off of those sold by JC Whitney?

[V7Goose]

The round gauges being sold by JC Whitney are going for $120. The set of round Emgo gauges is being sold on eBay by Saber for about $52 shipped. There's another seller on eBay - SportingForLess - selling gauges that look the same for $60 shipped, and in their ad, they claim that they're having their gauges made for them in Taiwan because the Emgo gauges have a huge calibration issue: "Those are top quality sync gauges, specially made for us from taiwan manufacture, they are not cheap "??GO" gauges. (we used to carry "??GO" brand sync gauges, due to the quality problems, 25% of those gauges are out of calibration, we had to send them back to the distributor, we no longer carry them anymore)"

 

 

Goose, your gauges are from JC Whitney, and have served you well, but we don't know if they're from Emgo or not. Has anyone purchased and used the Emgo's or those being sold by SportingForLess? Is SportingForLess full of bologna, or are the Emgo's a cheap knock-off of those sold by JC Whitney?

My gauges are so old that whatever brand name they carry is meaningless - parts source and manufacturing techniques have undoubtedly changed over the intervening 30+ years.

 

I do know that JCW sells a lot of EMGO products. I also know that JCW sells a mix of good products and crap, and it is not always easy to guess which one you are going to get until it arrives. But JCW's customer service and return policies have always been top-notch to me. Any time I call them and complain about the quality of something, they authorize free return shipping.

 

I do not personally have a particular opinion on EMGO brand products, but I completely dismiss the statement you quote above for two reasons. First, it comes under the heading of a self-serving statement from someone trying to sell their own product. Secondly, since these gauges can be calibrated, how can they be "out of calibration"?

 

I personally never, ever, never never buy anything off ebay - just my choice. But last year when this subject came up I did a little internet searching on various terms like "motorcycle sync gauges," "vacuum gauges," etc, and I found several sources for this gauge set for under $50. I would also tend to believe that any four gauge set on a blue plate that said Carburetor Synchronizer is almost certainly the identical set. I tend to believe that if a similar product is being made by two different manufacturers, they are going to be at least a little different unless one is deliberately trying to make you think you are buying a specific brand label!

Goose

 

BTW - both pictures of the four gauge set shown earlier in this thread look identical to my old one except that my plastic valves are green instead of white. Mine also came with the four long metal rods used to reach in and attach to the intake manifolds on a typical inline-four bike engine. There is not a brand name on my gauge set - there is a tiny little sticker on the back that says "Made in Taiwan", and the instruction say "printed in Taiwan." That's as close as it gets.

Edited January 26, 2010 by V7Goose

[Tom]

The round gauges being sold by JC Whitney are going for $120. The set of round Emgo gauges is being sold on eBay by Saber for about $52 shipped. There's another seller on eBay - SportingForLess - selling gauges that look the same for $60 shipped, and in their ad, they claim that they're having their gauges made for them in Taiwan because the Emgo gauges have a huge calibration issue: "Those are top quality sync gauges, specially made for us from taiwan manufacture, they are not cheap "??GO" gauges. (we used to carry "??GO" brand sync gauges, due to the quality problems, 25% of those gauges are out of calibration, we had to send them back to the distributor, we no longer carry them anymore)

 

 

Goose, your gauges are from JC Whitney, and have served you well, but we don't know if they're from Emgo or not. Has anyone purchased and used the Emgo's or those being sold by SportingForLess? Is SportingForLess full of bologna, or are the Emgo's a cheap knock-off of those sold by JC Whitney?

"Thats where I got mine,Sporting for less and yes I had to calibrate but it is VERY easy with the screws inside the glass. Ive synced my carbs once and they are remaining that way. The only complaint I have is the cheap rubber hoses they put in the kit..Relace as soon as you get the gauges,other than thaT GO FOR IT. TOM

[atlm]

I would also tend to believe that any four gauge set on a blue plate that said Carburetor Synchronizer is almost certainly the identical set. I tend to believe that if a similar product is being made by two different manufacturers, they are going to be at least a little different unless one is deliberately trying to make you think you are buying a specific brand label!

Goose

 

BTW - both pictures of the four gauge set shown earlier in this thread look identical to my old one except that my plastic valves are green instead of white. Mine also came with the four long metal rods used to reach in and attach to the intake manifolds on a typical inline-four bike engine. There is not a brand name on my gauge set - there is a tiny little sticker on the back that says "Made in Taiwan", and the instruction say "printed in Taiwan." That's as close as it gets.

 

I did a lot of comparing of the pictures of the "non-Emgo" gauges at SportingForLess and the gauges being sold by every other reseller, which are all listed as Emgos, and they look identical to me, also. Every detail is the same, down to the colors and writing on the gauge faces. Also, on 3 of the other websites (including JCW), the only complaint about the Emgo gauges in the user reviews are about the cheap hoses, which mirrors Tom's experience with those from SFL. So, I totally agree that SportingForLess appears to be trying to trick people into buying theirs, which makes me not want to buy anything from them.

 

The price differences from store to store are nuts, ranging from $52 to over $120 shipped. Saber's price on eBay is the lowest I've found, so I just ordered a set from them. Thanks for all the information!!

Edited January 27, 2010 by atlm

[atlm]

I received my gauges from Saber yesterday in the mail. That's crazy fast shipping! And they were packed very, very well for shipping by Saber. They gauges are much nicer in real life than they look in the pictures.

 

They're a lot bigger than I expected (a good thing). I thought they'd be small, the size of dash gauges, but they're nice and big, and will be very easy to read at a glance. They're the same as those described by Tom, with a calibration screw behind the glass and a tiny little sticker on the back that says "made in Taiwan". I will replace the hoses, as they're almost as hard as plastic, but that should only cost a couple of dollars. The restriction valves look fine, though, for the once or twice a year I'll probably use them.

 

Thanks again everyone for all of the information!!

 

As a side note, a few years ago some people were bashing Saber because of their own personal bad experiences. Since then, Saber seems to have changed their practices, as they have incredibly high customer feedback on eBay. Also, the only recent negative postings I saw about them have been from people who read the old posts, and were repeating what they read, not anyone having any bad experiences. From their eBay feedback, Saber seems to be going out of their way to try to make sure people are happy. From my purchase experience, I'd highly recommend them. Fast shipping, great packing job, and the best price. I'm not sure what more you could ask for.

 

[Tom]

I received my gauges from Saber yesterday in the mail. That's crazy fast shipping! And they were packed very, very well for shipping by Saber. They gauges are much nicer in real life than they look in the pictures.

 

They're a lot bigger than I expected (a good thing). I thought they'd be small, the size of dash gauges, but they're nice and big, and will be very easy to read at a glance. They're the same as those described by Tom, with a calibration screw behind the glass and a tiny little sticker on the back that says "made in Taiwan". I will replace the hoses, as they're almost as hard as plastic, but that should only cost a couple of dollars. The restriction valves look fine, though, for the once or twice a year I'll probably use them.

 

Thanks again everyone for all of the information!!

 

As a side note, a few years ago some people were bashing Saber because of their own personal bad experiences. Since then, Saber seems to have changed their practices, as they have incredibly high customer feedback on eBay. Also, the only recent negative postings I saw about them have been from people who read the old posts, and were repeating what they read, not anyone having any bad experiences. From their eBay feedback, Saber seems to be going out of their way to try to make sure people are happy. From my purchase experience, I'd highly recommend them. Fast shipping, great packing job, and the best price. I'm not sure what more you could ask for.

 

 

Glad to have been able to help you in a small way..After you get them set up you will like them..Ive hooked a rubber strap to the holes on the bracket to hang them on the handlebars while syncing carbs.Tom

[GOODWRENCH]

Has anyone used the carbmate carb synchronizer? Getmetools.com has the best price on this tool ,has anyone ever used this compy?

[atlm]

The base unit only balances 2 vacuum sources at a time. The "4 carb kit" is just an overpriced 4-to-2 hose adapter, which would balance the left and right pairs.

 

So, to use this unit, you'd need to hook it up to one side and balance those 2 carbs, then move it to the other side and balance those 2, then hook it up to all four and balance the left and right pairs.

 

At $130 for the two parts, plus shipping, there are better tools out there for less money.

 

Just my 2 cents.

[bald josh]

just built my own the other day...@ 28 bucks and it made a world of difference. $4.00 for each guage 2 for clear tube and the rest on the valves. i read somewhere about dampers and different carbs and thought with the valves i could adjust to any bike i hooked it up to, im not sure i like the valves, might have to go to something fixed, but it works. gonna take the bike to a MC mech/buddy and will find out how accurate it is, my bet is it will be just fine.

Edited February 6, 2010 by bald josh
no pics

[MiCarl]

just built my own the other day...@ 28 bucks and it made a world of difference. $4.00 for each guage 2 for clear tube and the rest on the valves. i read somewhere about dampers and different carbs and thought with the valves i could adjust to any bike i hooked it up to, im not sure i like the valves, might have to go to something fixed, but it works. gonna take the bike to a MC mech/buddy and will find out how accurate it is, my bet is it will be just fine.

 

So long as the gauges are accurate it'll be great. Clipboard mount is a nice touch.

 

It'll behave better for you if you put the valves or other restrictor at the motorcycle end. The extra air volume between the restriction and the gauge will dampen the flutter.

[bald josh]

didnt think about that...makes sense, i will reverse the tubes and check it.

[atlm]

Accuracy is just making sure the gauges all read the same for the same level of vacuum. You can check the accuracy of any setup by connecting all 4 gauges to the same vacuum source simultaneously, via a 4 into 1 manifold. You can make a "calibration manifold" from 3 vacuum Tees.

 

If they're the same, it's accurate. If they're off, you can calibrate the gauges (if they can be calibrated) or make note of the difference and use that when calibrating your carbs.

 

Let us know how it turns out. If they're accurate, that's a great setup at a great price, and folks will want to know where you got the gauges and the valves.

 

[GOODWRENCH]

That looks like a nice set up were did you get the gauges and valves? thanks all for all the feed back.

[BJB]

Bald Josh,

Is that a model 3220 Equus guage? That is what i can see from photos. No longer available from Equus. Thanks.

[bald josh]

yes , equus 3220 guages, got them in the cheap bin at carquest, there were exactly four of them. the valves are from ace in the garden section, theyre for watering systems and so arent as precise as id like but will work for now. thought id try and find something made for air/gas that might be better. still got to test the sccuaracy as mentioned above.