Maintenance & Technical > KX500 Original

High Rev Closed Throttle

<< < (2/3) > >>

petro:
Ok so I checked for air leaks via the method described and all checked out to be fine. I did however find some interesting lube on the slide in the carb. I'm guessing this is a graphite lube. Is this a common thing to do. I have never seen nor done this before to a slide. The slide did however look a little worn especially on the bottom corners. I'm guessing this may have been a solution to a problem the previous owner had. I also noticed that the clip position was 2 from top. Its supposed to be at the 3rd from top right? Making the lean condition I was describing. I moved it rejeted and did a plug test. Looks perfect nice tan color. The previous plug was black but not wet (lean condition right?) Seems as if slide is still sticking though. I guess my question is whats up with the white lube on slide???? Good or Bad????

KXcam22:
Petro,
 Black plug is rich, white plug is lean, medium tan to dark brown is good.  The lube on the slide may have come from pressure lubing the cable, or the PO used lube on the slide.  I have never done that.  The slide will always look a little worn but it is never enough to cause sticking (that I have seen).  The mechanical things that usually causes sticking are the cable itself sticking or the throttle tube not returning.  I have once seen engine vibration do that.  A broke head stay caused the motor to vibrate side to side which caused the slide to bounce side-to-side and not return right away. Rare.  After that it is usually causes by a lean condition.  To go further on this you need to post your jetting and elevation.  If your pilot jet is too lean or partially plugged it can cause this.  Generally the needle is not the culprit.  Hope this helps. Cam.

petro:
Original setting from PO......

168 main
55 pilot
needle pos 2
air screw 1 1/2 turns

Problems.... Black plug, lean conditions, chocking, rpm took while to drop after wot and pulled clutch. Oh and i guess white lube s**t all over slide.

The white lube was that of graphite. I have heard of it being used before just never seen on dirt bike.

What I have done......
Checked for air leaks..... None
Cleaned carb rejeted
Main 165
pilot 55
air screw 1 1/2 turns
Clip pos 3
cleand white crap off slide
lubed throttle (properly)
Elevation 1,000ft temp this time year about 70-80 dry air
results.....

Tan plug reading with great throttle response and power
Just the right amount of pipe smoke from exhaust
Slide still sticking guess this is the prob which is causing long wind down and screaming when throttle is closed. No brainier!!!!


It seems as if the needle position adjustment (richer) with a tad bit leaner jet solved black plug problem.
Going to dunes in 2 weeks dont wanna have wot when Im not asking for it!!!

Hillclimb#42:
Have you checked the throttle housing? If the tube is too far in the grip will drag, I've had cracked throttle tubes, the little cable wheel on the Housing, needs to be clean and free. I don't lube throttle cables, myself. It will run into the top of carb. It should be snapping closed "Whack" Should have some slack, too. Is graphite white? Sounds like grease, or water and oil product.

KXcam22:
Petro,
  Excellent. Thats the detail I was looking for.  For 1000ft the 55 pilot is likely too lean.  I ran a 55 at 3000' and it got too lean in cold weather and would rev up like you are describing.  I would suggest trying a 58 (60 is stock and too fat everywhere).  Your other jetting is good.  Cam.

Navigation

[0] Message Index

[#] Next page

[*] Previous page