Jetting on 1978 kz650D with pods

I have tried to find the previous thread about jetting this particular setup. Basically I have a 78 kz650d1 and I have a set of 79 kz650 carbs that had the accelerator pump on them. However I am using the non-pump bowls off of my original carbs so essentially I am trying to jet a 78 kz650. I am going to be adding pods as the PO's neglected the stock airbox and it isn't worth saving.

My bike has about 18K on it, is stock other than the pods and a new set of slip on mufflers for the 4-2 system. They do not appear to be unrestricted so I am assuming that the only mod will be the pods. I will be riding about about 2000 ft elevation in temperatures ranging from 60-110 degrees during the year. Anyways, I am about to get some rebuild kits and new jets and wanted to make sure I was going the right direction. I was planning on a set of 107.5's and either a 15 or 17.5 . Would this be too rich for this bike during the hotter months? I will mainly be using it to commute to and from work and I would rather not be stranded out in the desert somewhere if I can avoid it.

Any thoughts or insights to rejeting my bike are appreciated. I would like to get it running as soon as I can so that I can see how much more money it will take to get it up and going like I want. Plus, it is always easier to convince my wife that we need to spend more on a running bike than on a dead one taking up garage space .

Thanks,
KC

I can tell you what I learned jetting new headers on my KZ750:

1) get the right main jet first. The main jet determines performance from about 1/2 redline RPM to redline at nearly full throttle. If it pulls hard and strong in that region, you have the right jet. Too lean and it will starve at higher revs, too rich and it will bog down as it is winding up.

2) Jet needle position: on mine, they determine the throttle response when rolling on the throttle from arond 2500 RPM up. If the throttle repsonse is weak, raise the needle to get a richer mix.

3) Pilot jets: these set the idle and very low RPM (and light throttle opening) running. If the pilot jet is right, the "sweet spot" for the idle mixture screw should be maybe 2 turns out from bottomed. Also, the bike should run smooth at smallest possible throttle opening as the revs climb slowly from idle to about 2500 RPM. Too rich and it will "surge" in that range. Too lean and it will be weak and also the mix screw will be backed too far out to get proper idle.

4) Bowl fuel level. Hold at about 2K in second gear and snap the throttle open: if it hesitates the level may be too low.

5) You can check the spark plug electrode color to see if the mix is right. A clean tan center is perfect. White is too lean, black and sooty is too rich.

Hope that helps.

Post edited by: bountyhunter, at: 2008/02/26 13:31