80 KZ1300 - Carb Syncronization - Vac Spec

I had a carb issue (bad/no idle); I removed, readjusted and reinstalled. Per the Kawasaki 1300 manual, the carb syncronization procedure is to tighten down the butterfly valves (dampner valves) until snug and then back them out one and a half turns. I had them on the bench and was fiddling with it and saw that the buttergflys were all snug. I opened and closed the throttle a few times and saw that everything was ok. There was no binding - everything was sync'd up - it looked good.

I installed and started the bike. With a little adjustment on the throttle cables and idle adjustment - it started using the choke, warmed up and settled into a real nice 900rpm idle. (Problem solved - it wouldn't idle before which is which I dissassembled them in the first place).

SYNC'g:
I installed the vacuum lines to three vacuum guages and I was amazed that they were already synced per the kaw spec (+/- 2psi). They were all at 5psi.

New Problem:
The bike reved out and was very smooth. It was running on all 6. However, there is a "flatspot" at 1000-1500rpm. There is no throttle response whereas it should be able to pull away in 5th gear off idle.

Question: Do I need to resync the carbs so they have more vacuum at idle (10psi?). My trusted kawasaki manual does not have this detail.

Or, is this a pilot jet setting issue? The pilot jet adjusting screw is set per the book - one and three quarters turns. Question: Does this need adjustments - in or out?

I've had the bike since 1980 - it has the original pilot jet and pilot adjusting screws. I'm using a K&N filter. I'm located at sea level and this bike has run great in the past in the same configuration.

Thanks very much for any suggestions.

-Tim

Post edited by: Tim_k, at: 2007/09/04 14:13

The minimum vacuum is said to be 14CmHg, p19 FSM.

I working through similar problems with the carbs on my 1300. If I can keep from fouling plugs 1&2, my bike runs fine without any flatness off of idle. I think I've got it sorted out but havn't had the time to put the miles on it since I made my last adjustments.

According to the sages at the KawaSixes group on Yahoo. A good starting point for the idle mixture screws is 3&1/2 turns out. I've currently got mine at 1&3/4 turns also.

KZCSI

Thank a lot CSI.

I'll re-sync it and let you know what happens.
-Tim

Tim_k wrote:

...With a little adjustment on the throttle cables and idle adjustment - it started using the choke, warmed up and settled into a real nice 900rpm idle...
SYNC'g:
I installed the vacuum lines to three vacuum guages and I was amazed that they were already synced per the kaw spec (+/- 2psi). They were all at 5psi.

New Problem:
The bike reved out and was very smooth. It was running on all 6. However, there is a "flatspot" at 1000-1500rpm. There is no throttle response whereas it should be able to pull away in 5th gear off idle.

Question: Do I need to resync the carbs so they have more vacuum at idle (10psi?). My trusted kawasaki manual does not have this detail.

Or, is this a pilot jet setting issue? The pilot jet adjusting screw is set per the book - one and three quarters turns. Question: Does this need adjustments - in or out?

I've had the bike since 1980 - it has the original pilot jet and pilot adjusting screws. I'm using a K&N filter. I'm located at sea level and this bike has run great in the past in the same configuration.

Thanks very much for any suggestions.

-Tim<br><br>Post edited by: Tim_k, at: 2007/09/04 14:13

That's asking a lot to pull cleanly away from idle in fifth gear. If sync is already even, wouldn't re-sync.
Would assure perfect ignition timing and advancer operation. Believe any pilot adjustment would be toward richer mixture, maybe 1/8 to 1/4 turn from best no-load idle.

Post edited by: Patton, at: 2007/09/05 19:10

Hey Patton,
Yeah, but it did. Lugging it down to idle in 5th and pulling away didn't provide the best acceleration but it did get me out an awkward situation and I bring it up because it did! It was running right. And, nothing has changed since then other than the passage of time.

I was not able to resync up to to the 14cmHg spec. I suspected a bad guage but tested it with a mityvac.

I checked the yahoo kawsixes site (thank you CSI. I saw that you posted that you had wet plug condition and once you corrected that, the bike ran pretty good. So, I'm going to check the plugs, recharge the battery, check the timing (thank you Patton - never did that).

Thanks again for the suggestions.

Followup to my idle/carbsync issue:

I was unable to sync the carbs. My guages were reading low (5cg/hg instead of 13+ per the spec -thank you!).

I did the spit test and found out that 3 and 4 were not running. So, I checked for coil resistance and then spark and found no spark. I replaced the plugs, ran the spit test and found that 3&4 were still not running. I removed, disassembled inspected/cleaned/inspected the carbs; reassembled, reset per my trusted kawasaki manual, reinstalled. It took 3 hours. It started and it ran perfect. To sync it took 1/4 turn cw on the right carb. Amazing, it took 2 sec. Apparently, there was some obstruction in the carbs. I had just cleaned these out 2 seasons ago and I ASSUMED they were good. So, the lesson learned (my error) is that if you don't ride regularly and your bike sits with gas in it, the problem will be in the carbs. It now starts instantaneously and idles perfect with great throttle response from 800rpm to 2000 rpm. It pulls from idle. Perfect!!! Thanks for the suggestions guys. Let the good times roll!

Hi Tim,

What happened to the 3/4 spark problem?

I agree that the vacuum spec from the manual seems outta line. I ended up syncing mine at -2.5 in Hg ( about -2PSI) and was satisfied with that.

Have you seen the Infra Red thermometers?

Them things are hotter n spit!

KZCSI

Hello CSI,

I have accel coils (per Dave's site) and found that Splitfires work great. I had problems with the NGK's. I put splitfires in all my vehicles. Even though this is a low budget operation, I did have a extra box of 4 spitfires. I ohmed out all the coils; the 3/4 coil was ok - 4ohms. I thought it might be open. I checked the plugs and they were sparking from the center conductor to a point in the surrounding ceramic (not to the electrode) which looked to be a failure. The plugs were wet but I didn't think it should arc that point by the ceramic. Ordinarily, I would have cleaned them to see if would correct it but in the excitement of finding a problem (and maybe the solution)... I swapped in new plugs. The cylinders starting firing. (I'll have to clean and check 'em later.)

Yeah, I've heard about infared thermometers but never priced them out. The spit test is a fast and dirty go/no-go test and it would be nice to get an actual reading for each pipe. That would be interesting to see and even more interesting to troubleshoot. I read that you can adjust the pilot screw and see the difference in the exh pipe temp!!! ???

When I was having real problems making the min vac spec of 14 ... I cleaned the carbs and adjusted the butterflys per my trusted kawasaki service manual all the way down and back out 1.5 turns ( as I recall ...). After installation, the vac was up at 15 on the left and middle carbs and I only needed to turn the right adjuster -in- 1/4 turn to get more vac. (increase the reading). It took 15 sec. I guess the dead cylinders were pulling down the running cylinders and causing me to add throttle to keep it running. ... or something like that!!!

I'm going to run it every day for a week and see if it keeps in tune. I took it out yesterday and it screamed. I was just putting around the local roads at 4000rpm in 2nd&3rd and revin' it out to 7 just to see what it would do and it was it was really responsive. That one ride was worth all the time, confusion and befuddlement over the past month of sundays.

I'm going to start looking for one of those infared thermometers - it would have been handy.

I do have a fuel leak in my pingel tap. It's very annoying and stinks up the garage. It actually drips. I'm going to write a new post to see if anyone knows how to rebuild them. I'm really disgusted because it has been leaking since it was brand new. Pingle has a quality problem. I've heard of this happening. They won't repair it since it out of warranty.

Let the good times roll!