Kawasaki KZ 200 carb float height tuning

My 1978 Kawasaki KZ200 has been running moderately rich for a few years. The oil stayed relatively clean, so, even though the bike hesitates off idle, I did not address the issue by reducing the float height.

This year, I decided to reduce the float height from 4mm, and, after an odyssey of bending the little tang and remeasuring, which is not exactly a fine tune method of adjustment, I finally got the float height to around 6mm., maybe a little over. The spec is 4mm to 6mm measured from the top bottom of the gasket at the top of the float bowl.

Then, with a new plug, I ran 25 miles through a range of rpm up to 8500 or so, and, pulled the plug.

Pictures of how the plug looks now are at this virus free, google photos link.

photos.app.goo.gl/NCnViGmqeVPXCtd87

I wonder if any of the folks here have experience looking at plugs? I would appreciate any and all feedback. I am somewhat loathe to move it again because bending the tang is so prone to overshooting one's desire outcome, but, I can if need be.

Thanks and this is my first post.

Mike

Welcome.
And good luck. There’s some great information and folks here, and a great searchable trove of past posts and tips.

I’m no diagnostic expert, but here’s a couple pictures from a manual for generic spark plug symptoms;

I don't think your rich running was caused by your float setting. I don't know that carb well but it appears to have a fuel/air screw. If you back it out a bit you will lean the pilot circuit out.

At 4 mm you were in spec. At 6.9 mm you are out of spec. I suggest you have another go at setting the float level....try for 5.0 mm. Here is an easier way to do it, although you have to remove the carbs from the bike to do it. Not a big deal in my view.

www.kzrider.com/forum/3-carburetor/61368...n-setting-fuel-level

hardrockminer and flying frebole:

Thanks for the information and posts on this topic, my first to the forum. The detailed off carb procedure is excellent information. The photos of the spark plug are useful as well.

After nearly 2 weeks of experimenting, and, not really having a good way to measure from the "bottom of the gasket surface" on the KZ200 carb, I did finally, come up with an exact method to measure from the gasket surface in the top of the carb to the fuel float height. Seems obvious in retrospect and I wasted a bit of time.

I have set, as shown below, the carb float height to exactly 5mm (random chance outcome on what was to be my last go at it with that little tang on the float).

Method and outcome shown below. I took the bike out for a 30 mile ride after this, with the idle screw set exactly at spec turns out, 1 1/4, and the bike runs better than it has in all the time I have owned it.

Thanks for all the input.