Hot cams and smoothbores - how should it idle?

I think they are the real thing - the previous owner said he bought them from Redline. And looking at Patton's pictures, the parts look the same as mine. Maybe my verbal description was inaccurate.

Here are some pics:

Thanks for the pics.

Perhaps blocked by angle of the photo, but not seeing a bottom-located pilot mixture screw.

Good Fortune!

Hi Patton,

Each carb has a pilot screw on the bottom, at the front of the float bowl. I couldn't get the camera in there far enough to show them.

Thanks, Mike

Those are 29 Smoothbores. I doubt there are pilot fuel screws.

Actually, there are no pilot fuel screws. Look at the photo. It's just a casting that looks like they should have them. That's normal for the latter 29's.

I have to agree with Larry, Dave(OMR), and Patton, until you make sure everything else is in spec messing with the carbs is going to drive you nuts. I can however say that your cams would have to be some serious monsters to cause poor idle, my .410's idle fine and my brother has a .435 in. and .410 ex and idles fine at 1100 rpm.

I can see how it might look like the pilot fuel screw is not there from that photo. Be assured, the carbs do have the pilot fuel screw. I've taken them off the bike several times. Here's the best picture I can get, trying to scrunch the camera into that space between the starter cover and the carbs.

Last night I managed to improve the idle immensely.

I took off the Dyna timing plate, lubricated the ignition advancer and then timed the ignition with a timing light. The idle doesn't "hang" anymore. The bike still doesn't idle really well at 1,000 rpm's but it's a big improvement.

Next I will see if I can get the pilot air screws tuned a little better and sync the carbs with a manometer.

Thanks for all of the suggestions, this forum is so helpful. Especially to a guy like me in Honolulu, where there aren't many KZ1000's around.

If there's a pilot fuel screw on them, it would be the first rack I've ever seen with them :blink:

I do know there are some KZ dragbikes over there. No idea which island the track is on though. If you ride to the track you're sure to come across some good help locally though....

Another thing just popped into the brain... CAM Degreeing!

With after market performance cams, they most likely have adjustable cam sprockets. Possibly they weren't degree'd properly or the sprocket adjusting nuts loosened... Possibly your off a tooth or two in the timing chain count....

I know, a lot of possibilities but that's how the game plays for until you get into her and confirm a few things, no telling what the PO did or didn't do...correctly... :S

start with simple tune up and maintenance stuff like valve adjustment,while youre adjusting the valves you can check the cam chain and numbers on cams.
yets see you got a 900 punched to 1105 many years ago with a set of big carbs /big cams/ported head?/and who knows what else
chances are the guy who built the bike origionally rode/beat the piss out of it which is to be expected,so be ready to repair/replace some things as you go.

If the head was clearanced to allow the cams to turn, then most likely they are larger then .400 lift. Do what you can to find the manufacturer and call them for a cam card,if they are like Webb cam they will gladly e mail you a copy. If the card specifies just one clearance spec , say.006 , instead of a range as factory manuals do, use it as a bare minimum and from my experience don't be afraid to clearance them a several thousands looser.

A big cam bike is not wanting to idle at 1000 rpm. Here is a vid of my bike with andrews 3X. I have a good tune here and it is ideling alright.

These vid are of the bike when I had some funky 28mm carbs.

Click on images.

Go to omr's build thread to see his bike idle. I believe he has his idle bumped up a little. Roy