Maintenance & Technical > KX500 Original

Help Tuning, no idle

(1/5) > >>

bandit88:
Hey guys,
A couple weeks ago I picked up a 91 KX500.  Bike had been sitting for a couple of years and needed a little tune up.  I am running into an issue with it running pretty poor down low and not wanting to idle. Its a bit odd.  To get it to idle at all I have to have the idle adjuster screw all the way in.  It acts very rich and starts first kick when cold without the choke.  When first started it idles fine and high and soon loads up and idle speed drops.  Once up to temp it idles for 5 seconds then turns off.  I keep leaning the pilot jet and am at the point that there is definitely something wrong.  I am at 5000ft, jetting so far is: 40 pilot, 155 Main, OEM needle and slide, top clip.  2 turns on air screw.  Runs good wide open.  I am running VP110 with Motul 800 at 36:1.  Troubleshooting done:
-Carb is clean
-Float height is good
-New spark plug
-New AMR ignition coil, with NGK boot and wire
-Flywheel looks good,
-Stator coils test to spec
-New oil in transmission, Redline 80w
-New UNI airfilter
-No transmission oil lost
-No residue in flywheel cover
-Fresh top end, good compression
-as far as I can tell kips is carbon free and operates correctly
-New OEM fiber reeds
-Piston installed in correct dirrection

At this point I am a little stumped.  I keep thinking ignition but everything tests good and spark is a nice blue color.  Anyone have any ideas or suggestions? Thanks

alward25:
52 pilot and a 160 main is what I ran last time I ran from 4k-7k ft.  I would definitely go up on the pilot.  Sounds like it is not getting enough juice down low.  I would still look at going up on the main.  What exhaust u running?

bandit88:
Thanks for the response.  I was running a 55 pilot and kept stepping down from there.  Would 4 stroke really bad down low and has been getting a little better leaning it up.  Still starts first kick without choke which tells me its rich and something isnt right.  Pipe is a FMF Gold series with stock silencer.

Thanks

Friar-Tuck:

     I read you are not experiencing a loss of trans oil, however It really doesn't take a whole lot of oil to migrate into the crankcase to foul out your plug.
   Run the bike until it stalls out.    Pull the plug, you will be able to smell the burnt trans fluid on the plug electrode if in fact that's what's going on.   I may be all wet here...(ya pun intended :-D ) 
 It only takes a few minutes, won't cost much and the smell of burnt trans oil is easily distinguished.
  Tuck\o/

Foxx4Beaver:
I wouldn't go any leaner on the pilot yet...unless you're fully prepared for a melt down/seizure.
Since you say you're still having problems, even after changing the pilot size several times, I myself would do a leak down test...since you didn't say you have done one yet.
If it's got an air leak of any kind, it'll be impossible to get it jetted correctly, and to run correctly.
Good luck, and keep us posted.

Navigation

[0] Message Index

[#] Next page