KDXRIDER.NET

Hi.
I use my KDX 220 as a dualsport. I ride alot of dirt roads. Sort of like sight seeing type of ride. Cruising at low speed. I'm lugging it, in order to get that quiet comfort zone.

I'm noticing that it is fouling plug very often, like after every full day of riding.

When I used to ride in the woods, the plug never fouled.

I don't mind changing plug often. It's easy to do. Takes 5 minutes. And plug is dirt cheap.

But will I damage the engine to lug the engine like that? And to run often with fouled plugs?

If it's bad for the engine, I'm thinking about selling the KDX and getting a new CRF250L.

nothing bad lugging the engine if your jetting is appropriate. If too fat, you might get more spooge and gum up the valve faster though.
if you are fouling plug, this suggest the pilot is too fat. Check the jetting section (see my sig), you may want to go down 1 size on the pilot and test.
As for:
" I'm thinking about selling the KDX and getting a new CRF250L"
NONSENSE! if you were here I'd so you'd come back to your senses

you could also try pulling in the clutch and giving it a quick rev to blow out the build up

but this would be a quick fix though, you should check your pilot jet as stated before

And for goodness sakes, let her out to run around the woods and chase after other KDX's once in awhile, stay out late, run through a tank of cheap 2-stroke oil, get mud in all her crevices...tough parenting advise, but she will thank you for it!

Team Grean...

How would I know if the valves are starting to stick?

There is only one valve and it's the KIPS. You can check it's function to a degree by taking off the little round cover with a screwdriver (a quarter works great too) and revving the bike. No oil will come out. No springs come shooting out or anything. It's just an inspection cover. When you rev the bike you should see some movement of the mechinism at WOT. If it moves then the valve is working. It may not be 100% but it is doing something.

ROADSTR6 wrote:There is only one valve and it's the KIPS. You can check it's function to a degree by taking off the little round cover with a screwdriver (a quarter works great too) and revving the bike. No oil will come out. No springs come shooting out or anything. It's just an inspection cover. When you rev the bike you should see some movement of the mechinism at WOT. If it moves then the valve is working. It may not be 100% but it is doing something.

The part about the only one valve is not entirely true. The KIPS is a system that is made up of three valves that work together.

rbates9 wrote:

ROADSTR6 wrote:There is only one valve and it's the KIPS. You can check it's function to a degree by taking off the little round cover with a screwdriver (a quarter works great too) and revving the bike. No oil will come out. No springs come shooting out or anything. It's just an inspection cover. When you rev the bike you should see some movement of the mechinism at WOT. If it moves then the valve is working. It may not be 100% but it is doing something.

The part about the only one valve is not entirely true. The KIPS is a system that is made up of three valves that work together.

exactly
it is nothing like a intake or exhaust valve like you would find on a 4 stroke engine, but actually a mechanism that changes the exhaust port timing depending on what RPM the motor is running at
this allows you to have a higher compression at low RPM (top of exhaust port os closed by KIPS)
then when you reach a higher RPM the KIPS valve opens which allows the motor to run at higher RPM without the detonation you would get if the exhaust port would be as low as it is with the KIPS closed


more info is found here
http://www.dirtrider.net/justkdx/kips.html

Okay, I stand corrected. I know the KIPS consists of three valves but for some reason the OP's post made me think that maybe he didn't understand how the KIPS works and was referring to valves in the four stroke sense, with intake and exhaust. My post, while maybe not 100 percent technically accurate, was speaking to the entire KIPS powervalve as a whole unit as opposed to a set of intake/exhaust valves. Sorry if I confused anybody. I do believe the meat of my post was correct though in explaining how the OP might do a quick check to determine if the powervalve (ummm.....all three of them for you KIPS techs) is functioning.

What I meant was how do you know when it's time to clean the valves?

I pulled the pipe off and peeked into the cylinder. And from what I can see, the valve looks very dirty. I just cleaned it and rebuilt the top-end, about 8 months ago.

Is it possible to install the KIPS incorrectly so that the valves don't open/close at the right RPM?
I'm wondering if that's why my bike doesn't run good during mid-RPM.

post some pics of what you see in the cover slot.
the only reall way to know if the valves are gummed up or "carboned" up is inspecting them. You might be able to see some of it through the exhaust port.
If you did the top end 8 months ago, and you installed "clean" valve (removed all the carbon build up and spooge) it is unlikely that they are gummed up (unless your jetting is waaaaay off).
You usually clean the valve when it's time for a top end.

you can install the sub valve backward, but if you actuate manually the system it's pretty obvious when they are wrong.
If you didn't check manually, I think you'd know, your bike would not run as good as it was before.

what do you mean by "dirty" valve?
dirty as in covered in spooge (that black oily stuff)? (that's normal) or do you see carbon deposit? (the hard black stuff)

scheckaet wrote:what do you mean by "dirty" valve?
dirty as in covered in spooge (that black oily stuff)? (that's normal) or do you see carbon deposit? (the hard black stuff)

I saw black spooge. I also saw carbon. Hard to tell how much there was from peeking thru the exhaust port. Piston and cylinder look fantastic.

The bike runs pretty much just like 8 months ago after the rebuild. It generally runs good. But it just have that flatness feel to it at the middle of the RPM range.

I thought maybe when I put the KIPS back together, I might have missed it by one tooth or something.

If it's flat in midrange (1/4-3/4 throttle) it's a needle issue in the carb. I'd try changing the needle clip position, probably down 1 position to start (will richen the midrange).

i agree.

Go Green