KDX250 will not idle...

[kmx125r]

Hello All,

I've been fussing with my 1993 KDX250 trying to get it to idle. I bought it a couple weeks ago, and have been fiddling with it ever since.

Here's the data...

main 162
pilot 42
slide #5
needle stock
clip 2nd from top
A/S 1.5 turns out
plug BR9ES

It starts fairly easily, but I need to keep blipping the throttle to keep it from dying when I ride slow. Last night, I took the carb apart and cleaned it thoroughly, set the float, put it back on, cranked it up (much to the chagrine of the neighbors I'm sure, since it was after 9PM!!) but it did the same thing.

Actually it fouled a plug real quick and wouldn't fire back up until I put another plug in it. But even with the new plug I had the same results. Need a hotter plug?

I can crank in the idle screw (real far) and she'll idle OK, but then the next time I start it it's cranking up about 3000 rpm! No good.

Any thoughts?

Thanks.

 

[Matt90GT]

First off the jetting stock is way off. It will cost you about $80 in parts to get it right, most of it the slide.

First off, you need a #6 slide, then a CCH needle. This will lean things out. After that, drop to a 38-42 slow jet and 160 main.

With those jetting changes, you can swap to a br8es series plug. That will keep things from fouling and leaving a smoke trail behind you.

If you need parts, the cheapest place I found is Sudco:

http://www.sudco.com

The carb you have is a Kehin 38 PWK model

 

[Tom Ludolff]

I agree. I've had that same problem. Pilot is probably too rich.

 

[kmx125r]

Matt and Tom,

Thanks for the input...

I dropped the main to 160 and the pilot to 40, put the clip in the top slot on the needle. I put in a B8ES plug. This has definitely helped, but while lugging around the yard for a few minutes I sensed the plug beginning to foul up.

I just visited the buyKawasaki site to find the stock numbers. How do the needle numbers (R1366H to R1370H) cross over to the Sudco numbers (CCH, etc.)?

I'm getting closer, but still have a way to go... It started up much easier, but still seems a bit rich.

Thanks.

 

[Matt90GT]

The CCH is the same as the KX250 needle for the same year of bike. It is just the cross number there.

The slide is going to be the main thing. Once I swap over to basically the KX jetting for the year, but a smaller pilot, everything worked. No more fouled plugs, no smoke clouds, faster warmups, no more idle problems. I went back about 2 years on this board to find Daves old setup numbers on the carb jetting for the bike. Same as the KX but smaller pilot.

You may want to spray the outside of the carb, intake boot and airbox boot with some carb cleaner when the bike is running to detect any air leaks. The idle will increase if you find a leak.

 

[woodsy]

Hey KMX: I had the same prob with my 91 and found a weak needle and seat was the problem! If the float level is uncontrollable low speed load up will be too!
Woodsy

 

[kmx125r]

Woodsy,

Thanks for the information... I'll check it out, too! I'm determined to make it work right!

Jim