Less than $5 carb sync tool

I was contemplating buying a vacuum gauge set when I came across this:

www.powerchutes.com/manometer.asp

Apparently this method is more accurate, since the scale is much larger (using a yard stick), and all you have to do is even out the fluid levels on each side of tubing.

I'm gonna try synchronizing the carbs with this tomorrow and see how it turns out

 

i did the homemade carb sync thing a few monts ago also heres what i found
some of it may be helpful, but since i used the 4 hoses in a bucket method, i'am looking forward to your results
watch out on the inital startup if carbs are out badly that water can move real fast,real fast
warm your bike up first, then have a good fan to keep it from getting too hot
i used way more gas than i thought i would
the weight of the screwdriver on the screw can change the setting
one setting will effect the others go over them a few times
since i did mine all at once, i remember thinking changing to different carbs all the time would be a PITA
may i suggest making two of the type your using
if you keep the whole thing below the carbs the water would tend to go back in the hose and not over the top and down to the motor
back in the day they set mixture with a vac guage,tweak to highest vac then back off a little, but there are too many color tuners here to say that now :lol:
have at it, be careful

 

Hey, thanks for the threads links and tips guys, hopefully this will go well

 

The setup referenced is simialr to the diagram I made a few weeks ago.


Using two to sync all four at once wouldn't work because this setup measures difference in pressure between pairs (go fo 0) rather than absoulute pressure. So you could have one pair at 7 PSI and another at 10 PSI and the manometers would all read the same.

Also, since you are measuring relative pressures the carbs are synchronized when the fluid in both sides of the manometer are equal height. The scale is unnecessary so any method of holding the tubing would work.

Since you are measuring relative pressures I'd think 36" would be way longer than necessary unless the carbs are way off to begin with. If you make one I'd be interested to know how much difference in fluid heights you get from your bench syncing.

 

Ok Guys
I have a stupid question but one I don't have an answer. When hooking up to four carbs do you put a tee on number three where the vacum line goes to the pitcock?
Marty

 

no line to the petcock, since the first thing to do is take the tank off to get to the tops of the carbs
you need to rig up some kind of aux fuel tank
then to do all 4 at once make up one of these
i wish i could say i thought of it, but i found it on the web

 

Polock i was wondering if you have the link to where you found this?

and was also wondering what your impressions are on how this works? and what do you have the tubes filled with?

thanks.

 

Hey guys, I synced the carbs using two tubings. Although MiCarl brings up a good poitn about not being able to measure the actual pressures, the goal here is simply to equalize them. You sync 1&2 to be equal, then sync 3&4 to be equal, then I synced left and right, in theory they should all equalize. You can hear the difference in running quality right when you are syncing them. My bike runs a lot better at idle now, and the throttle response is better.

When I was syncing, I used 10w-30 motor oil, and if the carbs are off, the differences are huge. The vacuum will begin to continually suck fluid to one side and it would eventually bring it into the engine if you let it. The gauge is VERY sensitive, I found myself turning the screw in less than millimeter increments to get it level.

I still have a problem, though, when idling it sounds like the engine is having trouble staying alive. Kind of a surging sound for a while, then it will eventually die.
Bad spark?
I cleaned out the carbs thoroughly and especially the pilot jets/passages. I know for a fact all the plugs are firing, I electronically tested the coils and used pull-the-plug method, as well as recutting all the wires.
The plugs are quite ashy from running rich and one cylinder not firing previously... but would this result in a bad idle (and eventually dying) or is there more I need to look for?

 

For dealing with the gas tank, I just carefully rotated the tank backwards, so it was sitting where the seat was, and just made sure the fuel lines were still ok. That way I didn't have to rig an aux tank. You could remove the vacuum line and flip your petcock to PRI, and you'd be fine.

 

Polock, I have a question in regards to your sync tool.

I am debating whether to use a 2 tube or 4 tube manometer.

Since you connected all tubes together - the small tube between the 3-way tee's- is the length if this small tube crucial to the proper operation of this sync tool ? Since all tubes are connected, do all the tubes need to effectively be the same length?

Thanks

 

The tubes do not all need to be the same length.

 

http://www.vfrdiscussion.com/forum/lofi ... 16200.html

 

Thanks Polock think am gonna give that a whirl this weekend, it should be interesting as i have never done anykind of synching before.

can the carbs be synched without a yics tool??

 

Nice pic Polock. I used a four way connector instead of two T's for simplicity.

Also used Transmission fluid in mine as the red colour is easy to see and make sure it's not getting away on you at first startup.

FOr those deciding on the two or four tube design, I recommend the four.

When you do it with four you use the same principle but you will find when you make an adjustment to the right pair the left pair will "move" on you. You will find yourself adjusting contantly across the carbs to get it "Rick" :wink: perfect.

Don't scrimp on the homemade tool, spend the extra $2 and go for four. It's worth it. 8)

tichuang, you got a grin now using a two tube design, use the four tube design and I'll be able to see your beaming grin from over here in Oz. :wink:

 

This is debatable some say yes and some say no.

Personally, I get better results without the YIC's tool but my bike is old and tired. DOing it without covers up some problems like minor air leaks and bad valve settings. My belief (tried and tested for ME) is that without the YICS tool you are syncing your carbs for everyday riding conditions as you don't ride with a YICS tool inserted do you?.

Others will disagree and that's fair comment but my YICS tool has cobwebs on it and will stay that way.

Of course Yamaha states it is required for tuning but they also state mixture screws are preset and shouldn't be touched either. :wink:

 

OK wanna look like a pro?
You gotta act like a "Pro"

If you are persistant you can find deals like this all the time
http://cgi.ebay.com/ebaymotors/Motorcyc ... dZViewItem

YES, YES, I know there are environmental considerations!

One who owns something dangerous needs to exercise caution and act responsibly..... kinda like a motor vehicle or a really fun bike?

I've found that with my old sync stick, which had one broken tube, that, the 3rd line missing was too big of a PITA.
So I bought a new one that all 4 tubes work on..... WOW!!! WHAT A Difference!!!

Be advised that mercury is getting hard to get nowadays and will only get harder to get!

Sorry to all Greenies who this offends.
Just my .02

I do compliment the creativity of those trying to fond an alternative!! What a PITA that is, I don't have time for that.

 

I'm sure I know the answer to this, but you don't have to have the carb sync tool below the carb or anything like that, do you?

 

OK, ignore my last post in this thread (which I believe everyone already is ). I figured out the position isn't necessary. One thing that I was wondering is how much fluid you guys are putting in these things?

 

Hmm I tried all of these with my old kawasaki.

I tried to make a home-made one like polack did and could not get it to work at all. Not sure if it was the wrong thickness or what. I used two stroke oil as I was cared of it sucking the oil into the motor. Maybe that was the problem.

Then I made one out of sewer ABS pipe and a guage, and aquarium bubbler valves and it looked as though it would work, until I spotted a Motion Pro carb stick set going for cheap on EBay this summer. I bought it and that is all I can say about that.

I can send someone the sewer pipe one if anyone wants to try it. I also stole the idea off the net somewhere...