KDX wont rev

[Manray]

Here's the problem. I have an 86 KDX (the motor is fresh, recently done over by Fredette) In gear she runs great and always has. In neutral if I twist the gas it runs up and then bogs. Like if I just finished a real slow section and want to clear the motor out I'll wick it up but it won't rev into the upper range. Reeds??

 

[agitt73]

maybe your hitting the rev limit

 

[spanky250]

Originally posted by agitt73
maybe your hitting the rev limit

Two-strokes don't have rev limiters.

Does it rev normally after it cleans itself out, like it is loading up?

 

[Manray]

No it doesn't clean itself out it bogs. If I'm in gear and underway (underload) the engine will rev up and run cleanly (a little sputtering) but with the clutch in it starts to rev then bogs.

 

[spanky250]

It sounds like it is running rich to me. With the engine under a load, it can burn the extra fuel, but with the clutch pulled in, there isn't enough load to burn the fuel, so the engine won't rev or run cleanly.

 

[fishhead]

The key here is the engine runs better under load than free yet is "sputtering under load" which indicates a rich condition as Spanky has stated. Engines require a richer mixture under load say 12.5: 1 as opposed to 14:1 for an engine under slight load. Lean conditions cause a surge or flat bog.

weak or cracked reeds can duplicate a bunch of problems that initially can sound like jetting. I would check both.