My bayou 300 will intermittently run rough when I hit the throttle, but it idles fine. Here are some checks I did when it was running good:
I checked out the 3 yellow wires from the alternator- at idle I have 18 volts AC between 2 of the legs but 0v on the 3rd.
Alternator resistance reads, 0.6ohms, 0.6 ohms, and 0.2 ohms on the 3 legs
Battery voltage is 13.5v
coil when warm ohms out at 3.4 ohms

When running bad
the alternator voltage reads 18v AC at idle
battery voltage 13.5v
coil when warm ohms out at 3.2 ohms

I put a timing light on it and when idling it sparks normally, but when I hit the throttle it sparks slowly like maybe twice per second. My timing light reads RPM based on spark and when idling it reads 1000 rpm, but when i hit the gas it drops to 500 rpm which indicates less spark.

It will act up for a while and then it will start running good again after about 5 minutes.

Any ideas on what could be wrong?

 

Did you reset the timing ever? Vavles being off will cause wot fail. As soon as you give it vas chokes off. Also ngk plugs foul real easy. Mine did this not long ago. Check the timing it was off 180 fix it. Then we had a wot prob plugs was fouled. Then we check the exhaust vavle and intske they where off by by a good 10mm. Think on klf intake 10-15mm and exhaust 15-20.

 

I did reset valve clearance and check timing. I'm assuming it's something electrical since it's an on and off symptom. It will go into a mode where it won't rev up at all and then it will kick out of it instantly. Any other thoughts?

 

Could you upload a video? Klf300 has the cdi the stator solinded, coil, plug. Change the coil out and plug. I had a plug fouled and swear is wasn't. Spark was awesome put a old plug in last night and she fired up. My wot was cause of vavles though so we set it 10 intake 20 exhaust. Shot for the coil if you where close I have a spare u could have. I have the pdf on our quad. I will pm you the link might help more.

 

Thank you for the pdf. I tested the pickup coil and ignition coil and they are testing good. The CDI box doesn't ohm out correctly. I'm guessing that is the problem. I'll replace it and see if it works. If not, I'll upload a video.

 

They are not cheap. So might want to out source on here or site for price. I know my local kawasaki dealer quoted me something around 260ish. Good luck glad it helped.

 

Hi , I have a 90 bayou 300 ..2 wheel drive...changed ignition coil..old one had a green wire on one terminal and a red/ yellow wire on the other..new coil had a black wire jumped from one terminal to the other , then one black wire coming off...did I maybe get wrong coil...or any ideas how to connect

 

Hi David Akkerman, I just order the same coil I think, plus I ordered a new cdi and rectifier. Did you figure out what leads go where? I was guessing and took off the black leads. No spark and no voltage at either green or red yellow wire while turning over. Looks like those wires lead back to the cdi? If you don't mind letting me know if you found anything out for it looks like this $7 coil should work for us somehow? Thanks, Nick