Uni-Sync Tool?

[Mattx2]

Hey Guys,

I still cant get the xs to run right. The carbs wont balance (without a gauge its pretty much a guessing game). So i was surfin the internet to try to see if some one some where made a sync tool without using the air barbs and i came across this.

http://www.aaenperformance.com/snow_carb_acces.asp

Do you think it will work on the xs?

 

[XSLeo]

Build your own. Cost about $5. Go to most any hardware store. Get 15 feet of 3/16 or 1/4 inch clear plastic hose.
To make the manometer. Unroll the hose, find the center, get a yard stick or any piece of scrap wood about 2-3 foot long.
Hook the hose to the yardstick with clear packing tape.
The center of the hose at the bottom of the yardstick, run each end of the hose up the sides of the yard stick, taping as you go.
Hang this tool up so the loop of the hose hangs down.
Put a colored fluid in the hose, I used tranny fuild, Enough so the fluid goes up about a foot in each side of the loop.
To use hook each end of the hose to the vaccumm barbs on the carb holders.
On the older models they have fitting holes in the sides of the carbs that you can get adapters to fit. If your carbs older than about 75 you will to do the dead cylinder method.
Once the hoses are hooked, start the engine, if the sync is close the fluid level in each side will be close, adjust the sync screw till the levels match.
It is very sensitive.

 

[scott s]

Have you tried bench synching the carbs?

 

[Mattx2]

I have a '75 without air barbs with a pamco. Ive tried to do the dead cylinder method but, im un sure how to ground the lead. I saw the picture of how to do it but im just confused when i see it. I know he welded something on the plug but i have no idea how that works or what to connect it to. I know i sound really ignorant but i just want to do it right without ruining my pamco or any other parts. Could someone expand on it?

I never heard of the bench method. How do i go about doing that?

 

[XSLeo]

To bench sync you have the carbs off the bike. Use a piece of paper like a feeler gauge to set the butterflies the same. You use the idle speed screws to adjust the tension on the piece of paper.
One way to ground the plug wire is to use a set of jumper cables. With the plug in the plug wire clamp one jumper cable clamp to the plug. Red Or black. Hook the other end with the same color to a good ground.

 

[pumps]

This might be kind of hard to see. Green wire with an alligator clip on one end. Other end wrapped around a hose clamp that is snugged up around a spare spark plug. Clipped the alligator clip to the cylinder fins. Need a better picture? I can take one if you really need it.

 

[5twins]

If you're going to be using the dead cylinder method all the time, you can make up some little grounding adapters from old spokes. A spoke nipple uses the same thread as the spark plug top so it will screw right on .....

Ground the cylinder by touching a long screwdriver between the adapter and a cylinder fin. With these in place, you can quickly jump from side to side and compare the running speed.

 

[Mattx2]

Thanks for all the posts fellas!
This helps me out so much, you have know idea!

Just one question though Pumps,
I see the green alligator clip attached to the cylinder fins and the alternate plug dangling from the lead. But what i cant see is how exactly the other end of the green wire is placed around the plug with the hose clamp. Did you just strip the wire and wrap it around the threads?

Oh and 5Twins,
Good thinkin on useing a spoke nipple! Way to use the ol'noodle!

 

[pumps]

I just pinched the copper between the hose clamp and the body of the spark plug. Went out and got you a picture. see? 5Twins I like yours and will make one up if I ever get some old spokes.

 

[Mattx2]

Im going to building it right now!
Your the man!

 

[5twins]

For the spoke tools, you want to make two so you can put one in each plug cap. That way you can jump from side to side without having to shut the bike off and move the tool.

 

[Mattx2]

I just put together this little guy and going to attempt to sync tomorrow.

 

[pumps]

That'll NEVER work the wire's the wrong color!
Seriously , I didn't come up with that set up. I just learned it from a more experienced member. My turn to pass it on.

 

[Mattx2]

Hahaha thanks again for all the help

 

[Travis]

As far as the uni-sync tool. I know a very experienced motorcycle mechanic who uses something similar to that all the time. It should work fine on the XS if that's the route you want to go.

 

[tx650]

Don't know if this can help but here goes,Start the bike and turn up both idle screws about a turn each and then remove a plug lead.
Now turn to the still connected side and adjust the mixture screw until it is running smooth and then adejust the idle to spec.
To do the other side is the same as above.Take care.

 

[Mattx2]

ok so i just picked up new plugs for the sync and i installed them. Then warmed the engine then set to 2,000 rpm, ( just using the butterfly screws didnt do the trick so i tweeked the air/fuel screw to reach 2,000). Next i grounded the right lead and decelerated the left side to 1,000 using the butterfly screw. Then i reconnected the lead and restarted the engine. I didnt see or hear much change. So i moved on. I grounded the left side then try to restart the beast. Nothing. i cant for the life of me get the thing to start.
And when i does start it wont idle on the right side. i have to hold it almost wide open. and thats with starter fluid.

What did i do wrong? Any suggestions?

 

[5twins]

Sounds like the right side speed is set too low. What year carbs are you working with?

 

[Mattx2]

'75 bs38. even at idle its now firing. i have new holders and gaskets so no air leaks. new plugs too. im lost and frustrated.

 

[5twins]

I would start by swapping your new plugs side to side. It's not very common but sometimes you get a bad one right out of the box. Then I would set every thing back to stock settings. Re-set both mix screws to about one turn out. Back the idle screws out until you can see light between them and the arms. Screw them back in until they just touch then give each one the same # of turns in (about 1 to 2).

You should have been able to raise the idle speed with just the idle screws. You shouldn't have had to use the mix screws too unless maybe their settings were way off to begin with.

If none of this helps, you may have a problem with that right carb. It may be dirty and have some plugged jets or passageways. With the Pamco and single dual fire coil, you shouldn't get spark problems on only one cylinder. Usually, you'll get spark to both or spark to neither.