carb sync question.

I put my sync gauges on my spectre 1100 yesterday to see how close they would read. I have 1 and 2 reading 10hg and 3 and 4 reading 5hg. I synced them together at 7hg. I really dont care where the needle is as long as they are all the same but that is the question, why can I not get all 4 to read the same no matter where I adjust them to. Can someone explain how to do this please. I do have the fresh air pump installed on it and I did plug it off when I placed the gauge on 1 and 4.

Assuming all carbs are set up the same, (jets, etc.) You may want to do a static sync (not sure of the model carb you have so this may or may not be required), check for air leaks around the boots and such and that you have good tight vacuum connections. Outside of that it would possibly be due to valve clearance.

All of your gauges have the restrictions in the lines, lines are all the same length? tried swapping the lines around, read the same?

What is static sync? All the lines are all the same length.

I think he means off of the bike and setting the throttle plates to the same opening gap. Bench Sync.
that's always a starting point. Have you swapped hoses around, get the same results? All have restrictors in the lines?

A couple of things to note here.

1. Some carb gauges don't read accurately.
2. Those old CV carbs are not nearly as easy to synch as a newer rack of Keihin CVK's are.


Any carburetor with a locking synch adjuster is fussy to adjust. It's something you get a feel for over time. Where as the later Keihin CVK carbs used by Kawasaki has spring loaded philips head screws for synch adjusters. Much nicer arrangement because you don't have to fuss with a lock nut

You can check your gauge by hooking the lines up, one at a time to one vacuum tap. Note the reading.

I am following up with the syncing my cv bs34 carbs. I moved my clip on my needle to the bottom groove hoping it would get rid of my slight hesitation from idle to quick throttle while in gear. I cant really tell if it made a difference. I moved it up from the third from the bottom groove. It seems as if I had more pull in 2nd gear when it was there. I may move it back, or at least to the 2nd from the last groove. I do have the original air box so I am debating on going back to that setup. I did not jet this bike myself but I did get the original exhaust and jets that came with the bike stock. What would anyone think of going back to the original box would I have to put my oem jets back in? Thanks for reading.

Now it is starting to make sense to me, finally. You got the bike with the Pipe, and Pod's.
The Po would have put a Jet kit in it. Now what did he do? One of the popular Kits also includes a drill bit, for enlarging the small hole on the bottom of the slide. But there are also kits that would even include a different spring/ rate.
So I would look at the #'s on the jets to try and determine what you have. Also if possible measure the hole in the bottom of the slide valve. Dyno-Jet is the popular company, and with those Mod's the PO would have most likely gone to Stage 1. Maybe this one?
www.dynojet.com/pdf/2310.pdf

And yes to having to put the stock stuff back, or nearly those parts. It may still want a bigger main, pilot, or needle. Shimming the needle up with a small washer can be done. It would be a good Idea to get the #'s off of the all the jets you have, so you know where you are and what you can go to.

ok so I need to measure the hole that is drilled in the bottom of the slide correct and I will pull the numbers off the jets. The guy I bought this bike from really didnt know anything about it other than he checked the valves and gave it a tune up. If I had to guess the engine was rebuilt because it has almost 10k on it and still has 190 +/- 10 on the compression. And that was cold and with all but one plug in throttle wide open. I fiddled around with it again today seems that I have taken care of the hessitaion from idle to acceleration but not when I am at 60mph and snap the throttle it jerks then goes which it did not do that before. I checked the plugs and I have black around the thread area but the tip is paper bag color. I still may e running rich, I think I will move the needle back up one. Or should I adjust my adjustment screws?

I ment almost 20k miles on it not 10. The guy I bought it from had only owned it for about 3 months and only was able to ride it a couple of times before he needed money for whatever.

If you want to keep on tuning with those Pods, there is info in "File Base" for Throttle chop. In order to get readings you have to be on that circuit for a while, and not the others, or readings are mixed. So From the sounds of plug color it is rich, but in which circuit? If it hesitates then goes when opening the throttle then that sounds like a bit lean on the bottom. Besides Idle, the pilot Jet also supplies the small transition circuits. You may be able to open then screws a bit, but how far they are out now, will help tell you if the jet is to small. Out more than 3 turns I would say it would like a bigger Pilot. But that is if thee is nothing affecting the adjustment. I saw where you were pulling off there fresh air system. If done then make sure all is air tight.

Ok I looked at the drilled hole and it measures .118 dia. I have not looked at the jet numbers yet. I think I am going to leave the fresh air system on. I think I have it running decent. BTW I think I found a small hole in #4 slide diaphragm. That would mess with my tuning correct. Maybe at higher speeds or would it affect the whole throttle. I think next weekend I am going to go back to the air box if it isn't to much of a pain.