I have a 2003 Kawasaki Prairie. All stock. Bought in non running, with new top end, said he could never get it to run right after the engine work. The quad will start easily everytime I try, but will ONLY IDLE. If you touch the throttle at all it dies. If you turn the choke on it dies. The exhaust wreaks of fuel and the plug will be sooty rich in no time.

Here is what I have done.

Brand new fully charged battery. New plug.

Compression test. 87 PSI - My local bike shop said this is acceptable because of the KACR, compression release.

Leak down test, Passed with flying colors.

Checked timing and valve clearances. All dead on.

Carb, cleanest carb you will ever see. Rebuilt with all new internals, runs identical with stock keihin jets, and rebuild kit jets. Float level set, dead on per manual. Slide and diaphragm look good. Air/fuel screw set at stock # of turns. This carb has been gone through many times.

Checked exhaust for restrictions, its clean. Eveything is stock but I have tried airbox lid off,on, muffler off, on, any combination I could thing of. It always runs the exact same.

I do not know where to go next with this, I have triple checked everything I know to check. If theres anyone with advice on where to go now please chime in, I would really appreciate it.

 

If it is running rich it is getting to much fuel or not burning what it gets. Most likely cause main jet needle not set right. Some can be adjusted, some cannot. Or the choke not closing, either the plunger sticking or a cable fault. I did have a Honda 300 with these symptoms and it turned out to be the CDI, it would rev out if you were very gentle on the throttle but if you opened it normally it would die as soon as it got off idle.

 

The only was this needle is adjustable is to make it richer with washers underneath. Im to the point where I was just gonna get a different carb until I priced one. Geez.... there proud of them.

 

After reading another thread I decided to pull the carb off one more time and polish the slide. Its slid smooth by hand and didn't look bad at all the way it was.

I polished the slide and body in a very non aggressive way for awhile until it was very shiny. Put it back together and it kinda wanted to take revs around mid throttle. It still choked me out of the garage with fuel with both doors open in less than a minute, but at least I got to hear it past an idle.

Thoughts?

 

Ok heres an update today. I had a 400EX I had to do a top end, and carb rebuild on at the house today. After I got the 400ex carb done I couldn't help but putting it on the Prairie. It ran the exact same crappy way.

I decided to put the Prairie carb on the 400ex and it ran pretty darn good.

Put the 400ex carb back on the 400ex. It ran great also.

So now im totally baffled.

 

Looks like it is an electrical fault then. The mixture doesn't burn properly so it appears to be rich. I would change the coil first because it is cheapest, but like I wrote above, it turned out to be the CDI on the Honda. I'm not convinced that 89psi compression is enough, but any faults should have shown up on the leakdown test.

 

Its charging while its running, It came with an extra cdi when I bought it, and no change when I switch them. Iv been checking grounds this morning. but im not very good diagnosing electrical issues.

 

Just curious to see if this helps. Pull the coil wire leading to the cdi. Check resistance on coil tab to ground. Should show a small ohms resistance reading such as 0.3 or so. Check secondary(bare coil wire back to coil tab) Should be around 6K ohms or so.Plus check for any breaks/cuts in the coil wire that could be shorting to ground. Plus most 5k resistor plug caps should ohm out around 4k-4.8k ohms.Don't know if this helps or not.

 

I will check that this evining, heres a little update from today.

Ok I have checked all the grounds I could find, all checked out. I had a 2nd CDI that came with this, tried it. ran the same.

Noticed the 4wd switch seems to do nothing with it running. Im not even sure how to actually put this in 4wd.

Lastly, I unplugged the ecu just to see if it turned over. and it started and ran like it always does. Should this thing even have started with the ecu unplugged? What exactly do these control?

 

Doesn't have anything to do with the electric starter. Will be able to turn over with the cdi unplugged. See if this helps on the basics of how the ignition system works.