Anyone who has used Bill Murrin carb synch tool

[XSive Okie]

All the other tools have a four guage set-up, where you balance two guages to the same Hg reading. Using Bill's set-up with a single guage, does anyone know what range a guy should look for?

[motoman]

All the other tools have a four guage set-up, where you balance two guages to the same Hg reading. Using Bill's set-up with a single guage, does anyone know what range a guy should look for?
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Haven't a clue what your talking about.........other than you are balancing ALL four to the same reading..........Single gauge?............let me know how that all works out......

[XSive Okie]

It's in the tech tips, and he uses a single guage with a fish aquarium valve and says to set one carb at a time, while the other three are shut off. Doesn't make sense to me either, so I was hoping someone could explain. If the first carb reads 13 (for example), and then the next carb 17, do you adjust the first carb to match, or make the second carb read 13? Oh, hell, I'll wait til winter and my tax refund and spring for the good set-up.

[James England]

We're all in the same universe on this forum, all right. I was looking at vacuum gauges on eBay tonight. I thought about that single gauge thing and decided I'd rather look at 4 needles at the same time. They cost about $55 here in the UK.

[skids]

I don't know, but 0 to 12 inches should work if you don't let off the throttle after having the rpms goosed.

[BA80]

It's in the tech tips, and he uses a single guage with a fish aquarium valve and says to set one carb at a time, while the other three are shut off. Doesn't make sense to me either, so I was hoping someone could explain. If the first carb reads 13 (for example), and then the next carb 17, do you adjust the first carb to match, or make the second carb read 13? Oh, hell, I'll wait til winter and my tax refund and spring for the good set-up.

Or, you could get it running fair and ride over to Tulsa. I have a decent set of guages.

How far IS enid from here anyway?

[crazy steve]

I just got done building one of those set-ups rather than spend $50+ as I already have a good vacuum gauge. I like this idea as it eliminates any chance of misadjustment due to variations in gauge calibration.

As far as using it, you're not 'looking' for any particular number, just that they all match. The number three carb is the one that you adjust the others to, so starting there with whatever reading you get, adjust 2, then 4, then 1 to the same reading, in that order, and the order is important! You'll probably have to go over them a few times until you get the same across the set. The thing to remember is that number three is the 'base'; the only way to change the vacuum reading on that one is by changing the idle speed adjustment, and that will affect all of them.

[ManagerMike]

Allright, I'll ty to make sense of the single gage setup as I use it myself.
As described in the tech forum, using one gage, an aquarium valve gang, and some sort of reservoir to smooth out the pulses into a readable vacuum level, one can construct a sync tool.
The valve gang is used in its environment to distribute air from an aquarium pump to various devices in the water, say a filter, bubble wall, or one of those treasure chest/bubble decorations. The valve gang allows the aquarist to turn the air on or off to the various devices as needed.
In a sync tool applicaion one uses it kind of in reverse, the pump is replaced by a vacuum reservoir or chamber, and each of the four valves is connected to the carb vacuum ports, and the gage is connected to the chamber to read the vacuum in it.
With all four valves closed, the chamber "sees" no vacuum, opening one valve, say cylinder one, and waiting for the vacuum reading to stabilize, a reading for that cylinder can be established. Closing #1 valve and opening #2 allows the vacuum reading for #2 cylinder to be established and so on.
By sampling one cylinder at a time instead of reading all four at once, a bit more time is consumed to make the needed adjustments, but a whole lot of money has been saved, and you don't have to calibrate four gages, or spend a ton on a four way manometer.
Hope this helps

[greatnw]

I'll chime in on the one valve. I made one described somewhere here on the forum. PVC pipe capped on one end, some sort of plumbing plug on the other. Tapped two nipples into it and hooked up the aquarium valves. Took me a while to understand that patience and a fan on the engine to keep it cool helped a lot. Bike runs well, but I'd like to get a carbtune and see the difference.
You really are simply looking to start on one carb, can't remember which sequence and start syncing to that reference point. Pretty simple and I have to be close to right on. I had the gauge and the pvc pipe so it was a cheap build.

[WMarshy]

IIRC #2, 3, and 4 should be adjusted against the #1 carb... sounds like a long process using one vac guage...

[crazy steve]

IIRC #2, 3, and 4 should be adjusted against the #1 carb... sounds like a long process using one vac guage...

Nope, everything gets adjusted to #3. That's where the throttle cable hooks, and where you make your idle speed adjustment. And order is important; if you adjust 1 before 2, when you adjust 2, 1 will change. What you're doing is adjusting throttle opening on each carb to get the same vacuum reading. So you adjust 2 and 4 to match 3, then 1 to match all.

[BA80]

Nope, everything gets adjusted to #3. That's where the throttle cable hooks, and where you make your idle speed adjustment. And order is important; if you adjust 1 before 2, when you adjust 2, 1 will change. What you're doing is adjusting throttle opening on each carb to get the same vacuum reading. So you adjust 2 and 4 to match 3, then 1 to match all.

HUH? There are only 3 adjustments for the sync on a set of carbs.

You cant adjust INDIVIDUAL carbs that way. 1 & 2 need to be adjusted to match with a SINGLE adjusting screw between them, and then 3 & 4 the same way and then with the adjusting screw between 2 & 3 bring the two pairs together to match.

And I agree that the single guage sounds like an awful lot of labor switching back and forth between cylinders because there is a lot of rechecking and small corrections that need to be made normally.

[DAVINCI]

And then after you're done with that exercise in futility, go ahead and set your idle mixture to the highest vacuum on which cylinder? - pick one. Then go to each other one and adjust it's idle mixture. Then go back and do your one-gauge synch dance again.

[natemoen]

HUH? There are only 3 adjustments for the sync on a set of carbs.

You cant adjust INDIVIDUAL carbs that way. 1 & 2 need to be adjusted to match with a SINGLE adjusting screw between them, and then 3 & 4 the same way and then with the adjusting screw between 2 & 3 bring the two pairs together to match.

+1, Greg has the correct order here.

[XSive Okie]

Or, you could get it running fair and ride over to Tulsa. I have a decent set of guages.

How far IS enid from here anyway?

About 90 miles straight west on Hwy 412, like your leaving out of Sapulpa or Sand Springs. Might PM you someday about coming over and using yours when I get some time off!