I mentioned in an earlier post that my KX5 was running soft off the bottom on...


I mentioned in an earlier post that my KX5 was running soft off the bottom on my last ride.bI had not done anything different from earlier rides. Thinking that the reeds might need replacing decided to order a Rad Valve to try.

Installed today, set jetting per their recommendations as a starting point. Bike started clean, revved easy so thought I found a solution. Went to ride and it's even more soft on the bottom now. Played with jetting and didn't make that much of a difference.

Anyone one had similar issue and come up with a solution???? Possible a coil issue???

Any help will be appreciated....

%d comments
  • Timing?9

  • Been no changes though..... Just wondering if it could be electrical....

  • All you can do is test em. Usually if it's the Cdi it's an all or nothing thing. If it's coil then...... Stator is kinda all or nothing too. Checked your plug gap? When is the last time you cleaned the carbon off your exhaust valves?maybe the wadding I. Your silencer is coming free. Douched out your carb real good. Air filter clean ?

  • Did top end last fall so shouldn't be KPIS

  • Seal on the crank getting bad. Plug is tight? Head and cylinder tight.?

  • Are the brakes dragging ?

  • There's some things to keep you busy

  • old age and your too afraid to hold it flat ???

  • Never thought of that one!

  • Soft at bottom? I don't know what that means exactly however but I'm going to ask. 1. What is your compression? If under 175lbs time to rebuild upper. 2. If starter fluid spray in the left case timing wheel makes your bike surge your crank seals are leaking air changing your mixture of your carb. Then rebuild bottom. Hope this helps. My bike surges so I must split the cases. Hey I got 15 years on rubber seal which is amazing.

  • Ron, is it possible that the power valves are stuck open?

  • That could be it too. You'll know in two seconds when you pull the lever with your fingers. Take off the plastic cover see if the pin is in.

  • Was running OK the last time I rode in FL 3 weeks ago... I'll check this weekend to see but that's what it feels like

  • Sometimes the get gummed up a bit and then when they sit for a while they open and then stick, I aint saying that's it but it does happen