DIY Carb Sync, oh what fun...

[tomacGTi]

This one is long, but entertaining...

So one of the things I've been meaning to do to the Bandit was a carb sync; especially since I didn't know if it had ever been done before. I have most of the paperwork for the bike through the years, but I never saw anything mentioning it on there. I was thinking about either:

-Borrowing Rob's sync tool at some point (hour to get to his house)
-Buying one of my own ($50-$100)
-Having the shop do it ($85-$150)
-Making one (>$25)

I was cruising around the Kawasaki Rider Forums site (http://www.riderforums.com/showthread.php?t=2821&highlight=carb+sync)
(you have to be a member to see the pics) and saw probably the most ingenious manometer and thought that why the hell not? Total cost, including buying a doorsill plate to use as the back (they didnt have any yardsticks) was $20. A short trip to the Pep Boys yielded the necessary 3 way tubes to link all the tubes. If you hazard to make your own, this is what you need:

-24' of 3/16" internal diameter vinyl tubing (goes right onto the vacuum nipples)
-1' of 1/8" int dia vinyl tubing
-yardstick
-2 3/16" vacuum "t's"
-zipties
-and mechanical pencil erasers to make a damper for the tubing
-remote fuel source
-a long (longer than 10") #2 phillips

There was a thread in the forums not long ago about making a manometer but it was only for 2 cylinders at a time. This one is actually nice that it does all four at once. The dampers are absolutely necessary because it would be impossible to read the water column unless otherwise. If you don't use the dampeners, the columns will literally dance around and splash. It's possible to still do the sync, but a total PIA

I didn't use pencil erasers as I didn't feel like going back out so I used the plastic tube that holds the ink of a Bic pen and a red lubricant straw (the one with the smallest hole possible. These will fit into the 1/8" plastic hose that will the fit inline into the 3/16 hose perfectly. The pics in the forum give a very good idea how it all fits together. I used washer fluid in mine, it's gravity is better than water and it's easier to see.

I used a water bottle, a length of 5/16" vinyl hose and the outer casing of a Bic pen (goes right into the fuel feed of the carbs) for my remote fuel source (ghetto, but the price was right=$0). Using the hidden prime on the petcock, I filled the container, pinched off the vacuum feed and got started.

My carbs were so out of sync that the initial turn on after connecting everything up after warm-up, the bike sucked all of the fluid into #1. I refilled and readjusted so that the #1 water column actually stayed put. #1 and #2 were about 10" off (the manometer is filled approximately 18" up the yardstick) and 3 and 4 weren't even on the map (since all the fluid was at #1). By the time I got 1 and 2 remotely close (1" of water = .07343" of mercury) 3 and 4 were ridiculously off from one another (by at least 8") as well as from 1 and 2.

After refilling my fuel source 3 times and constant cursing, I was finally able to bring all of the columns within 1/2" of one another and I called it done. Here are some things that if you decide to take this on yourself, I can advise...

-a long phillips is a necessity

-if your carbs are out as bad as mine are, sometimes it's easier to try to sync 1-2/3-4 first, that way you have a better water column to work with.

-The 1-2/3-4 screw is a complete whore to get to (if you have an airbox). It sits angled and there is no easy way to get to it without revving the pants off of the bike. I finally resorted to shutting it off, making an adjustment and turning it back on again.

-small turns of the screws are all you need, even pressing on them will show up on the manometer.

-Make sure your remote fuel source is vented, or else it will hydro lock and no gas will flow.

-I was very happy to have the bike injest washer fluid versus mercury

In all, from the start of the procedure, not including building the manometer, took about an hour. It took about 30 minutes to build the manometer. The bike is back to idling at 1400 instead of the 2k that I had it previously and it has much better throttle response. It was too cold by the time I was finished to give it a ride, but I'll try it out tomorrow.

Good luck! The only downside is that the manometer is about 3 feet long with 10" of hose hanging out of it. At the very least, you didn't spend so much, there's no mercury and it looks like an out of place squid.

-Randy

[tomacGTi]

Finally got the bike out today as the temps reached a balmy 41*...

Throttle response is better all around and it certainly feels like there's more power everywhere. Funny what happens when all the carbs decide to work together.

If you haven't sync'd your carbs, it's well worth the aggrevation to do so.

-Randy

[PitterB4]

Cool, Randy.  Good write-up.  Thanks!  

[Farre]

uhh, i have trouble visualizing this... do you have a pic?

[tomacGTi]

These are the images from the Kawi forums.

I cannot take any credit whatsoever to the creation of the manometer, I only built one for myself.

 

This is the whole manometer in use. 4 tubes ziptied to a yardstick and hung on the handlebar. It is filled halfway with fluid.



If you look closely, this is where the original creator used pencil erasers that were predrilled with a very, very small drill bit for the dampeners. He then used the insulation of a telephone wire inserted to keep the opening open. This is where I used the pen ink tube/squirt tube in the 1/8" hose instead. The 3/16th tube fits perfectly on the carb vacuum nipple and the 1/8" tube fits perfectly into the 3/16".



These are the crossover tubes that allow the manometer to sync 4 carbs at once. You'll need about 4" of 3/16" tube to make the crossover so get a couple of extra inches.

Once again, I take no credit for the creation of this, I merely followed instructions and built one myself.

-Randy

[b4cruz]

I built the cheapo paint stirrer 2 at time carb sync
and it just took way too long without the cool
crossovers and eraser thingies the other DIY kits have
however I think for compactness and lack of mess
I'd prefer four gauges and avoid fluid all together
for practicallity it really is the best even at $50+

I actually enjoyed building the carb sync and doing it that once.
But if I had to do it again, it would be more pratical for me to
buy the 4 gauges and get the job done quicker.  However If I
didn't have time to wait for shipping or backorder/restock, I'd
buy the crossover bits, double my set up and do it
liquid DIY again. THANKS for sharing the INFO!!!!

http://www.jcwhitney.com/autoparts/Product/tf-Browse/s-10101/Pr-p_Product.CATENTRY_ID:2004169/showCustom-0/p-2004169/N-111+10211+600014252/c-10111

http://www.holeshot.com/tools/carb_sync_gauge.shtml

[BrianM]

The thing that sucks about guages, is that you have to zero each of them in at the start....

I bought these back when the dollar was stronger against the Euro (er, more likely the pound ~ they're old) ~ $65 to my door as I recall.  No fluids, self calibrated, simple and easy to store:



Sorry for the flash glare...  Carbtune II out of england.  I'd used the mercury filled versions from Motion Pro, and they just weren't conductive to easy transport.  I guess it helped that I had a mobile MC repair business at the time too, easy to justify the cost when you're using it a couple times a week.