Rejetted and needled carbs now sync needed??

I rejetted the carbs on my 78 kz650 D to 17.5 for the pilot and 110 mains, and moved the needle clip down one for 4-1 streight header and pods. Do I need to Sync the carbs now? I've been told that I do, but I don't see why? They should be the same as before. What would have changed? Thanks

If it ran fine before you should be ok,but,it would not hurt to make sur everything is right on the money.

I pulled the slides to get to the needles. Is there a way to sync them without paying $60-80 dollars?

Omaha Rider wrote: I rejetted the carbs on my 78 kz650 D to 17.5 for the pilot and 110 mains, and moved the needle clip down one for 4-1 streight header and pods. Do I need to Sync the carbs now? I've been told that I do, but I don't see why? They should be the same as before. What would have changed? Thanks

The throttle slide heights will likely have remained the same, but imo that condition doesn't assure equivalent continuing sync properties following the changes.

Am thinking change in pilot circuit alone (larger pilot jets) might require re-sync, never mind cumulative effect when also changing intake (pods) and exhaust (4>1) on performance of pilot circuit.

Performance of each cylinder at idle and lower rpm may react differently to the changes.

Would hook up the sync gauges and take a look.

A slow steady even idle with minimal cam chain noise, and strong pull away, usually indicates a pretty close sync.

Good Fortune!

In the last two years or so I've rejetted and adjusted needles over a dozen times on several sets of carbs while doing o2 sensor experiments. Every time I would check the carb sync and it was always off if I did anything with the top ends of the carbs or if I removed the carb rack. I sometimes change the main or pilot jets without removing the carbs, in that case the sync usually stayed the same.

You can screw up the sync if you just grab the carbs and wiggle them around a bit. I've seen the differential go from 0 cm difference to over 2 cm difference by twisting the rack the wrong way. (And Ive seen it on 650's and 1000's as well as many 550's.)

It's best to give it some hard rev snaps to let the carbs settle in position, then do a final sync with disturbing the carbs as little as possible.

Here are some notes on manometers:
home.comcast.net/~loudgpz/GPZweb/Manomet...meterNotes.html[/url