First kdx. weird sputtering problem, jetting?

[runtis]

Hey guys! I just recently picked up my first KDX for 2k. it is a 220r frame with a 220 bottom end and a 200 top end. I beleive the years are 2000, 2006, and 2004, respectively. It runs great and the whole top end is practically brand new, not even broken in yet. It has a lectron carb. The only issue is that no matter what rpm(although it is exaturated below idle rpm) and what throttle position, when accellerating the bike seems to misfire every 20 or so strokes...

It makes a loud, noticable break in the symphony of 2 stroke reverberation every 20 or so strokes- like its sputtering.

It feels like its running richer than elon musk, with a black spark plug, but even when I tried closing the power jet and backing out the metering rod 2 turns, its still seemed to run rich.

what should I do? check the reeds? carb? KIPS?

I beleive it has a new air filter in it.

Please, add your two cents. any help is appreciated, no matter how slight! I fell in love with this bike apon first ride!

-Ezra Norman

[Chuck78]

I would inspect the air filter yourself first. Is it dripping oil out of the airbox drain? Could be severely over oiled. My other big hunch other than perhaps a bad right side crank seal burning gearbox oil, would be that it has a fake NGK spark plug from Amazon or ebay, a bad spark plug cap, the fitting on the end of the plug wire that is, or a failing ignition source stator coil. A weak spark will cause delayed ignition which will cause the bike to seem to run rich, and a failing ignition stator coil can cause a weak spark as well as a failing or fake forgery spark plug. A failing stator often will get harder to start and begin running worse and worse at low RPM as the engine gets hotter and hotter.

[Chuck78]

I have recently learned that there are even more fake NGK spark plugs out there than I had previously known, with as many as 80% of the ones being sold on eBay and Amazon being forgeries of very inferior quality. I would throw in a new spark plug from an auto parts store, NGK BR8ES or BR8EIX , and take it out for a rip as soon as the engine is close to operating temperature, and see if it stopped doing it for a short time and if it begins doing it after the plug has had a chance to foul out. If it truly is just a rich mixture, the br8eix fine point iridium tipped spark plug will be much more foul resistant, although that's really just a workaround to fixing the actual problem.

[runtis]

Thanks for the fast replies! The filter is brand new, and if anything is a littly shy on oil. The spark plug has ngk stamped on it and looks like any other NGK, but Ill for sure throw in my spare BR8EIX I have been keeping for this occasion through my ever changing lineup of 2 smokers. That is, once I get time. The tranny oil is not low, but high. the pic taken is leaning th ebike slightly. There is no spooge, and the dude I bought it from started it for the first time in a month when I got there. I watched a nest or something fly out the exhaust whe it started firs tkick, so I knew he wasnt kidding me. If the right side seal were to be faulty, it should have been rediculously flooded, right? and lots and lots of white blue smoke? The trans fluid overfilled is not cuased by a faulty water pump seal, as shown by the full radiator. i am yet to check the other electrical components, but assuming htey are cheaper aftermarket options causing a late spark, could I not just account for that by advancing the timing by the flywheel? Thanks again, Chuck! Pics of everything below.

[runtis]

added reply for more pics:

[KDXGarage]

Cap pshed down firmly?

I would oil that filter. He didn't ride it for a month, but who knows when he last oiled it. The dirt sticks to the oil mostly.

[Chuck78]

the dude I bought it from started it for the first time in a month when I got there. I watched a nest or something fly out the exhaust when it started first kick, so I knew he wasn't kidding me.

Hmmm.... This could mean there is still some hornet nest material or something in there that's choking up the exhaust....

[Chuck78]

The tranny oil is not low, but high. the pic taken is leaning the bike slightly. The trans fluid overfilled is not caused by a faulty water pump seal, as shown by the full radiator. i am yet to check the other electrical components, but assuming they are cheaper aftermarket options causing a late spark, could I not just account for that by advancing the timing by the flywheel? Thanks again, Chuck! Pics of everything below.

Are you sure the water pump seal isn't slightly weeping coolant into the gearbox oil? Your site glass tells me it probably is, unless the bike was on it's side in a creek crossing enough to get water into the gearbox breather hose... gray milky oil is a telltale sign. The KDX water pumps don't typically dump lots of coolant into the gearbox the way a failed KTM water pump o-ring seal does, but instead they'll slowly weep a little at a time into the oil just enough to taint the appearance of the oil enough to raise concerns...





as far as electrical, I wasn't referring to the timing, although it wouldn't hurt to check that to see if it's within the 3 mark adjustment range specified, but I was rather referring to a failing stator winding or a failing or generic forgery spark plug giving a weak spark. Aftermarket ignition source stator coils put out slightly higher voltage than stock, which does in fact advance the timing on it's own, so full advance should not be used with an aftermarket stator because closer to the middle mark is actually the same dynamic timing as the full advance mark on the OEM stator in good condition. Then full retarded marking would be the middle mark or near it, and actual fully retarded (more high RPM power / less low end torque) would be slightly past the original fully retarded mark range. More advance gives more rapid throttle response down low and more low-mid torque, but less top end rev out.

[runtis]

Thank Yall for the help! Seriously this is by far the best forum ive been on so far. Yall's answers have been the fastest and most informative ive ever gotten.

Anyways, yes I shoudl oil the filter- good catch :)

the spark plug cap was pushed doen all the way, but it never had a satisfying pop into place. There seemed to be 2 metal washer ring things on the spark plug, probably causing the spark plug to ride a little high in the head. Is that the problem?

I think the sound of a clogged exhaust could be probable. what should I do to check/ clean it out?

Now that I think on it, i vaguely remember the seller telling me he replaced the stator becasue "the original didnt give enough power to spark it." How do I check if the one hes got in there is good, do i just go lead to lead with my multimeter comaring to spec in the manual? I would do that, but I put an aftermarket stator inmy kx250f that measured WAYY outside the manual's ohm readings... but it runs perfect and has proved to be one reliable beast.

Just drained the oil. Looks fine to me. Thoughts?

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The stator cover came off easily with a slight stench of old gas but there seems to be a flywheel wight or something in the way of seeing the timing... behind a red loctite bolt

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[runtis]

Ok so I messaged the dude I got it from. turns out it has a brand new bottome nd as well! Holy cow, I'm running an all new frankenstien motor! this rules out the bad crank seal and the bad water pump seal. This makes me wonder if the 220r pipe that is on it is not tuned to the 200 top end and maybe thats the problem.

[runtis]

I think I found a/the problem! lake of old oil sludge in boot. Got it cleaned out, ill let yall know when I try riding it tmr if it helped. Also pulled the reeds, they look flawless.

[KDXGarage]

Clean the mounting area, re-oil (or clean and oil) the filter, then throw a bead of waterproof grease around the rim where it seals so dirt does not get past.

Kawasaki had dealer information on models that had been sitting on the dealer florr for a long time to re-ooil the filter before sale, as it does drain down. I would assume your filter is blue where it pooled at the bottom.

That is the stock flywheel (rotor). It comes off with a 27 mm a 1.0 mm LEFT handed thread flywheel puller. I think the OEM tool is part number 57001-252. Grease the threads and end when in use.

[Chuck78]

Kawasaki had dealer information on models that had been sitting on the dealer floor for a long time to re-ooil the filter before sale, as it does drain down. I would assume your filter is blue where it pooled at the bottom.

That is the stock flywheel (rotor). It comes off with a 27 mm a 1.0 mm LEFT handed thread flywheel puller. I think the OEM tool is part number 57001-252. Grease the threads and end when in use.

***Grease the PULLER TOOL'S THREADS AND END***
not the tapered crank end or flywheel rotor taper... Just don't want anyone to misread that.


Funny story, I bought all new shock rebuild parts once as a slightly younger less experienced mechanic because "the shock is dripping oil on the floor under my KDX!"

Experience quickly cued me in to the fact that this was just air filter oil dripping down out the airbox drain...



Gasoline smell in the stator area means leaking cases or crank seal. Pull the stator and flywheel and look up the sanding + epoxy job to fill in the circular elongated slots around the crank seal area in the aluminum casting, as they are found to often be porous on Kawasaki cases of this era. Someone has written it up on here surely, at it's in Eric Gorr 's performance book. Pressure testing the assembled engine would be helpful. 5psi for 5 minutes.

[Chuck78]

What premix oil are you running?

You might want to check stator plate static timing and set it on the middle mark if it's got an aftermarket ignition source stator coil, as the reputable brands' coils are higher output and advance the timing in the CDI because of the added voltage, so the factory timing marls aren't correct, don't use the max advance mark at all unless voltage output is stock and it's a cheap off brand or OEM Stator

[Chuck78]

What premix oil are you running?

You might want to check stator plate static timing and set it on the middle mark if it's got an aftermarket ignition source stator coil, as the reputable brands' coils are higher output and advance the timing in the CDI because of the added voltage, so the factory timing marls aren't correct, don't use the max advance mark at all unless voltage output is stock and it's a cheap off brand or OEM Stator.

I would monitor the oil, it looks a little bit too much on the gray side, although it could be just a lot of clutch particles. The photo of your sight glass definitely makes it look like it might have had a bit of moisture in it. Hard to tell from the dark garage photo of the drained oil. It could be questionable though.

Unless the previous owner used gasoline as a solvent to clean the flywheel rotor and the stator area of the engine case, I think you need to pull the flywheel and stator plate and degrease the areas I mentioned above where it's like three semi-circular slotted windows with rounded ends, little recesses around the seal area. The aluminum casting is usually porous there and sometimes causes leaks into the crank case..

[runtis]

Thanks to all of you for the help! Geniuses, both of you! The first response was dead on- the old filter oil/ gas in the boot was the problem.

I cleaned the filter with gasoline and dawn and it cleaned up nicely. oiled it with k&n oil with a bead of grease around it for that nice seal.
I have not done the left-side crank seal check/epoxy yet, I just put the cover on and called it a day. Is it really that important?
I am running whatever oil gas mix the dude had in it before me. Didn't smell old, and I would hate to waste all of it in that massive safari tank by dumping it so I figured I would send it and ride with it :) 2 stroke smoke that smells like shrimp!

Just took her out for a rip and I was surprised by the power! The only thing left now is figuring out that mystery headlight... I made a separate post about it.

FOR ALL THOSE GLANCING AT THIS FORUM FOR THE SOLUTION: cleaning out the air boot from old filter oil/ ancient 2-stroke oil fixed it. Hope this helps!

[KDXGarage]

I have not heard of the oil issue on the 1995_ bikes. I thought it was just 1989 - 1994.

I would drain out that old gas. It's just a few bucks to have peace of mind.

[Chuck78]

The oil in the intake boot probably had veey little to do with any running condition unless it was flooding into the carb... Most likely the air filter was not oiled enough anymore and allowing it to run too lean?

The left crank seal area crankcase is definitely an issue if you had gasoline smell behind the stator cover, unless someone spilled a ton of gas on the cover and the wire grommet and wires weren't sealed enough to keep it out .

That's a common problem with the thinned out casting in those "windows" or slots around the seal in the aluminum crankcase halves. Casting porosity causes an air leak into the gases, and some gasoline can migrate out as well. The next time you've got some time and are doing bike maintenance, it doesn't hurt to tear into that, it's a simple project. M27 left hand thread flywheel puller required, Motion Pro makes a nice one. And some JB Weld, sandpaper, and paint thinner or brake parts cleaner