KDXRIDER.NET

Ok, this one has thrown me for a loop. Cold my 03-200 hybrid idles really high compared to when its warm. Just this past week installed new top end (piston and cylinder). no change. Had the RB carb mod done just prior to the top end. No change. If I set the idle when bike is warm, it is crazy high when cold, as bad as having the choke pulled up. Current jetting..38 pilot, needle in 4 clip, 152 main. 1 1/2 out on screw. Ron sent carb out with 40 pilot, got lots crisper with the 38. Have checked for air leaks around the carb many times. Reeds appear to be fine, no craks or chips. What the He** am I over looking?

that's normal. it will settle down once the bike is fully warm up.

Makes setting my new revloc a pita !!!!

ecojbr wrote:Makes setting my new revloc a pita !!!!

Well, you are supposed to get the bike up to full temp before making any adjustments, carb or otherwise.

It isnt just a small difference in idle, it really takes off. Adjusting the clutch must be done warm yes. It is idling so high cold it is embarrasing!!! I will get it, it is prolly something really simple I am missing, thats what is so frustrating!!!!

The idle speed on my KDX is annoyingly varying. When first starting from cold, it idles well (I have it set fairly high). After some slow woods riding, the idle speed drops considerably. After a high speed/high rev session, the idle speed returns to normal. I have inspected my carb and all of the parts closely, but I did not see anything wrong at all. I suspect a leaky float valve, though. It just does not bother me enough to warrant buying the parts yet...
I may try "T"-ing the vent lines though.

Dumb newbie question - how do you adjust idle once it is warmed up?

You'll have to buy one of those fuel injection programmers you see in the back of Dirt Rider Magazine and plug it into the connector under the seat...Oh wait, you just turn the screw on the left side of the carb.

The really small slotted screw is the air screw and the larger screw is idle speed. You should be able to turn the speed screw with your fingers.

Or maybe I misunderstood your question.

If your question is the mechanical part of adjusting idle speed use the screw as mentioned above.

If your question is what do you set your idle speed to (rpm), I just set mine so it has a stable idle. If it is so slow that it wants to die then I speed it up a little but not so much that the bike won't slow down when I let off the throttle.

How well it idles also depends on idle fuel mixture. If it's too rich it will tend to load up and sputter to a stop (like the choke was on too long on your lawnmower or something). If it's too lean it will tend to stall abruptly and never really feel like it wants to idle at a stable speed anyway.

Thanks, Brian. It really was as simple as the mechanics of setting the idle speed. I just haven't had to mess with it yet on my new to me KDX.

check your float height..it may need a little re -adjustment..that could cause your bike to run a fast tick over when cold (lean setting)...while its off check the breather pipes are clear of crud, also the carb intake rubber boot as that too may have a tear in it on the underside

cornishwrecker220 wrote:also the carb intake rubber boot as that too may have a tear in it on the underside

+1