KDXRIDER.NET

I'm re-evaluating the jetting on our 2001 220, because the pipe gets really hot. I mean hotter than normal. It smells like burning pipe. It has a gold-ish, gray toasted color all over.

It cooks when my son rides it, and I think he is probably revving it a lot more than I do.

The carb currently has:

142 Main Jet
Stock slow jet, throttle vavle, and needle (3rd clip from the top)
40 Pilot Jet
I think the Air Screw is 1.5 turns

Conditions:
60 - 80 degrees F
500 - 8000 ft ASL

Bike:
2001 220
FMF Knarly Desert (new, clean)
FMF TC II freshly packed
V-Force III reed cage (pretty new)
40:1 2R Yamalube
Nice, clean Twin Air filter
Snorkel removed, extra holes in a/b lid

plug looks good
no pinging
Excellent throttle response throughout the range
Coolant is NOT boiling over.

Any suggetions?

Barry

Could it just be the pipe is burning off the residue left over from making it? (Oil, plating, etc.) I have the same pipe but woods and it has turned a slight goldish color. How long have you rode with the new pipe?

I don't think so. It's got about 6 or seven rides on it now.
I have new FMF pipe on my KX as well, and it's nowhere near as hot.

I'm going to go up one size in MJ and PJ and see what Mr. Plug says.

B

You can always go back if it don't work out. Did you do any thing with the jetting when you changed the pipe?

My KDX 220 does the same thing when my son rides it. It has the RB mods and desert pipe. I ride it like a trail bike. My son rides it like a 125, Full throttle and he doesn't like to let off. When he pulls up to the truck the pipe is a little more discolered then when he left.

I don't think it hurts anything. Although I hate to hear my bike being wound up and ridden that hard I think it helps burn the crud out of the engine and pipe.

Ok, so maybe my son was not revving it so much as I thought. Turns out, for some strange reason in the past, I had leaned out the main jet, and the pilot jet was down to a #40.

So I returned the jetting to stock - pilot to a #42, the main to #145, and everything was fine.

Someone say hot pipes?

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