Carb sync

[pnut1236]

I just did a valve clearance check and now I have to do a carb sync, I want to know how everyone on here sync's their carbs. Do you buy the tool from Suzuki or Motion Pro etc or is there a way to make one, I have seen one made for bikes/atv's with 2 cylinders but not 4 as you have to hook them all up at the same time.

Another question is, since the sync port on the #4 carb is alot bigger than on the other carbs since it hooks up to the vacuum line, wouldnt there be alot more vacuum coming from it and would throw off the reading from the other carbs when trying to sync them together?

[92xjunker]

your sync will work for 4 cylinders, just takes more time. All sync ports are the same size. do not use the vac port on carb 4, cap it off when performing a sync.

[mykat]

I just did a valve clearance check and now I have to do a carb sync, I want to know how everyone on here sync's their carbs. Do you buy the tool from Suzuki or Motion Pro etc or is there a way to make one, I have seen one made for bikes/atv's with 2 cylinders but not 4 as you have to hook them all up at the same time.

Another question is, since the sync port on the #4 carb is alot bigger than on the other carbs since it hooks up to the vacuum line, wouldnt there be alot more vacuum coming from it and would throw off the reading from the other carbs when trying to sync them together?

You don't need any special tools, just a vacuum gauge. The best way to do it is to have two vacuum gauges, however you can get a nice set of 4 mounted gauges for like $30-40.

The procedure is simple. Get the bike to the syncing RPM (don't remember what it is, I think it's around 1500, you'll have to look it up) and hook up the left two carbs to the gauges. Adjust the screw in between the carbs until the vacuum is equalized. All that the screw does is change the difference in the angle of the butterfly valve between the two carbs.

Next do the rightmost two carbs. Once those are balanced, hook up the gauge to the two middle carbs, and adjust the middle screw, which adjusts the left and right side, NOT the individual carbs.

Static vacuum coming from a port is not affected by the radius of the port, however I do not believe that the side port on the #4 carb will give you a correct reading, for other reasons. To be safe, use the same topside port as on the other 3 carbs.

You'll probably want to rig up an external gas tank while you perform the sync.

[pnut1236]

thanks for the help, I have the manual but it is very vague. On the #4 carb all I see is the vacuum port, not a smaller sync port like the other carbs have unless im missing it somewhere. If I can find the sync port then I shouldnt have any other problems completing it. On a side note would it be ok to attach rubber hoses to the vacuum guages or do I have to use some special tubing when connecting them>

[TRPUT]

Unless your carbs are a lot different from mine, you use that petcock vacuum port on #4 carb for the synch - I don't have another option.

You can use standard vacuum gauges, but unless they are good quality you will get wildly different readings across the 4 carbs. Better quality gauges are more accurate and can be calibrated. Those gauge sets for $40 tend to be rubbish. If using gauges, you need rubber tubing but you will need to install a dampener into each tube to stop the needles bouncing wildly all over the place - just means inserting some smaller tube within the tubes to restrict them.

Long term, you are probably far better off to buy (or make) a decent manometer style gauge set or a Morgans Carbtune. The investment will pay for itself in a more accurate, faster job and less frustration.

[pnut1236]

your probably right, I was looking at the motion pro sync tool and it seems easy enough to use. Anyone on here have experiences with them? Also the bike seems harder to start would that be from the carbs not being sync'd after the valve check

[omnigsx]

http://www.fz6-forum.com/forum/how-tos/39891-build-your-own-manometer-throttle-body-sync.html