More on spoo....

[m0rie]

Goodness!!!! That plug would scare me to death. Mine are always at least the color of mOrie's avatar's legs.

Don't think i've ever had a plug described to me that way before...

[Indawoods]

Yes... m0ries legs are a nice mocha brown...

[Green Hornet]

My plug is colored similar to CC's and I just have some speckles on the fender. What a bloody mess. CC, is that with the unported cylinder FRP replaced or is that the FRP Prt cylinder? Did you replace your sub-valve yet??

[skipro3]

Carvr,
My KX250 looks exactly like your bike's fender and plug. That was using Mobile MX2T oil at 40:1. I've heard that oil is known for it's dry exhaust so that is why I tried it. Going back to SuperM cleaned up the spoo and the plug looked just a tad tanner than that ash grey.

I know you said it didn't used to do that, but I recommend experimenting with oil brands. What works for one rider and bike could have different results for another. I have several bottles of MX2T if anyone is interested in trying it. It did the same in my KDX as it did in the KX, so it's not going to be used by me any more.

[KDXer]

Hey, your back. I hope you sorted Bart out.

[IdahoCharley]

What a mess!! Wish I could provide some insight.

Plug tip looks good to me!! Inner shell (adjacent to center electrode) would be lighter colored if you were running lean IMO. For all you guys basing your jetting on the color of the center electrode you are missing out on throttle crispness if your center electrode is mocha brown colored.

CC - You mentioned that your bike is responsive and running well - just this spooge. Is there an operating rpm range where you feel the bike 'falls off' the power when the engine is not under load?

[canyncarvr]

re: most spooge

BTW, FTR and all...currently 38-152-DEK/4-#7TV

Said before, but....I've been on both sides of that (more lean, more rich). Also said before but not in this thread...the more rich the bike is setup, the less it drips. It doesn't run better, but it drips less. The current jet-set works very well from the standpoint of performance.

GH:
FRP ported cylinder, no RH subport drum. My unported cylinder is sitting on the bench awaiting an aluminum slug.

Fuzzy:

Yeah. I thought that too...kind'a funny after Inda's first reponse regarding timing with race fuel/octane boosters. If you find out anything of note regarding advance/retard 2/4s...please let me know.

Jason:

Heck no. (Jason is referring to the fact that I found my RH subport drum banging around inside my exhaust pipe awhile back.) Before I do that I'll put my spare OEM (unported) cylinder on..AND send my current cylinder to Langcourt to find out what they can do about all the pits in the plating USChrome (pics in the gallery) left behind. Ski has opined prior that he wonders about all the pits in my USChromed cylinder. Me, too!

Note that you can't see the mixture ring at all in the above pics. The color of the insulator tip doesn't mean anything when it comes to lean/rich air/fuel mixture. But...the flat of the thread ring does. Now...it's not pretty, either!

IC: Is there an operating rpm range where you feel the bike 'falls off' the power when the engine is not under load?

Not under load? No. Same under load.

With the exception of being a PITA to start (due to the plug being so wide), the bike runs terrific! Starts hot easily, idles forever, throttle response ideal. I'm often one gear higher than I think I am. 'Gee...2nd gear should pull better than this!!'...and I'm in 3rd. With the KX forks on, this bike is a joy to ride..the best it's ever run!! That's a large part of why I don't care if the RH subport drum is gone or not!

I use SuperM. Generally 40:1. The above pics are 50:1 (close to it). That mix ratio suggested by Mr. Fredette.

Ski:
Interesting ...about the Mobil. Good to know stuff like that about different oils. Heck..I just bought about three gallons of SuperM. I'll be using it for awhile.

Believe it or not...a .028" plug and a 40:1 premix ratio is worse drip-wise than the pics in this thread. That setup will leave actual drips on the fender!



All of this is posted just for fun, mostly. What with many questions in years past regarding spoo=too rich, what plugs are supposed to look like and such...this whole scenario is just too curious.

Yeah. There is a bottom of things to get to about all this. Neat!

Thanks to all for the input. I appreciate it. Well...except for KayD doing another hijack attempt anyway....

[KDXer]

Awwwww !!! But, but, but Mo & Vince did it first.... And you thanked them. Well I'm not your friend anymore anyway. Boo hoo hoo

[fuzzy]

Well, my suspicions were just confirmed by a reputable kart engine builder on another forum. Timing 'theory' is opposite on a 2T vs 4T. Advancing ign give more bottom, and less top. Higher CR needs less timing adv (retarded)....Not that this means you would lose any bottom as the higher CR would enhance power accross the band. I would be really curious to see how a slight timing retared would affect your issue. Sucks that it is so hard to adjust timing on a moto engine. Takes about 30 secs on a kart....Then again there is no trans, the timing is static, and the ign is mag type.

[IdahoCharley]

I suppose I could check myself but the bikes are put away for winter.

Doesn't a hole in the KDX flywheel line up with the mounting screws for the stator assembly?

I have adjusted one or two Jap bikes just by loosening the stator mounting screws and rotating the base and then retightening up the base without ever removing the flywheel. Just have to be able to see the reference marks.

NOTE - Hand impact driver recommended for loosening the stator base holding screws if this is the first time they have be removed.

[KDXGarage]

Any chance to just buy a subvalve and run the engine as it was designed to be run?

IC: I think you will need to pull the rotor to get to the screws. You need to remove the rotor, then loosen the screws and twist the stator within the mounting screw hole slots (there are slots for adjustability).

[IdahoCharley]

Thanks for the information Jason - I was just basically taken a stab that I had hoped may save someone from having to run down a flywheel puller.

I haven't felt the need to change the timing on the KDX 200. I just may bump it next year to see what changes can be felt.

[canyncarvr]

Yes.

Advancing timing enhances bottom end, takes away from top end.

Retarding timing does the opposite..enhances top end, takes away from the bottom end.

Retarding the spark timing on a 2-stoke motor transfers heat to the pipe..and pipe heat is big deal when it comes to making the 2-stroke 'supercharging' (cylinder stuffing) cycle work.

Mine is currently set to OEM. Well...to the mark anyway. I have no idea if the timing is or is not 2.0mm BTDC. It's on my list of things to do..make the marks, hook up a timing light, check the piston travel..to see if the mark on the stator is really 21º BTDC. I have had it on both sides of that. I used to change it every time I changed pipes (from FmF -30 to -35). I stopped that hassle when I got the rev pipe working better on the bottom end than the torque pipe had been working.

Haven't changed it in awhile. Time to readdress that issue I guess.

I'll retard it a tad..see what happens.

Yes, Mr. Who. The subvalve should be replaced. Guess that's on my 'list', too!

BTW...I haven't measured the stator..it's about 6" in diameter? That makes one º = .052" movement. That makes the total stator movement (1/4" or so each way?) good for about 5º +/-.