2001 220R with mysterious problem (running rich)

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tommy1
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2001 220R with mysterious problem (running rich)

Post by tommy1 »

Hello,

I’ve been into dirt bikes now for some 26+ years and have had a few bikes in that time. Some have never had any issues and some minor issues but I have picked up a 2001 220R that is really testing my knowledge. I’ve been tinkering with it for about 6 months but just can’t find the problem it has. I’ve spent countless hours searching the internet and going through forums but haven’t quite found a cure. So here is the story in a nut shell…
I have had a couple of KDX200’s over the years and loved them but always wanted to try a 220. I found a 220 that looked to be hardly used but in need of help and took it home. The previous owner had never ridden it, had owned it about 2 years and was in the middle of making it a supermoto. After a few days of pealing black rubber paint off it was starting to look like a KDX. The bike looked like it had hardly been used. The black primer was just starting to show through the green paint of the left side ankle area of the frame. I rubbed through the paint to metal with only 3 hours of riding. It is a little faded and minor corrosion so I think it spent time sitting in a car port. Story is owner prior to the guy I purchased it from crashed once and wouldn’t ride it. I did find and scrape off dried animal parts from the forks so maybe they hit a dog and wiped out. The gas that was in it was varnish. Over the past 6 months I have:
1) Cleaned fuel tank
2) new fuel petcock
3) New fuel line
4) Cleaned card 3 times
5) One new carb rebuild kit
6) New jet block gasket
7) New Pro circuit II pipe
8) New Pro circuit silencer
9) New top end (had stock piston)
10) New Boyesen power reeds
11) Cleaned all power valve components
12) Checked timing
13) Checked coil, cdi and stator
14) Leak down test (held 7psi for 3 hours)
15) New spark plugs
16) Tried difference fuel mixer’s (I use 50:1 in my Gas Gas)
17) Stock air filter (clean)
18) Snorkel removed
19) And most recently, put a 2001 KDX 200 carb on it
The problem is the bike runs really rich. With the stock carb I was running 35/135 jetting with the stock needle in 2nd clip to get a dry plug and plug would be dark grey to black with that jetting. Last I tried the stock carb I was 35/138 in fear of running to lean. Bike ran strong but always had a fouling symptom. When off the throttle it would load up then it take the next straight of way to clear it out and get full power again. When running down a hill using engine braking, if I pull the clutch in without blipping the throttle it will die. If I stop and blip the throttle (low rpm’s, no need for high revving) for 5 -10 seconds the bike would idle fine. Ride some more and it does the same thing again (down hill or on the flats) but when you stop it needs help with the throttle till it gets is fuel managed again and then idles fine. When revving the bike or engine breaking it has a ping ping ping on decal and has the same symptoms less the ping ping ping with the 200 carb. The 200 carb feels to have the same off idle torque, better mid range and better top end. 200 carb is jetted 42/152 with its stock needle in middle clip. Plug with the 200 carb is wet. Although minimal smoke out the pipe….

So, there you have it. I think its going to start costing $$ replacing things I tested that may not fix the problem from here. Anyone reading this have any ideas or suggestions to try??

Thanks & Cheers

Fyi: both carbs have the #5 slide
I live at 1300 feet elevation
2001 KDX 220R
2004 Gas Gas EC200
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6 Riders
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Re: 2001 220R with mysterious problem (running rich)

Post by 6 Riders »

Well, my first suggestion would be to get a new air filter. Just pick up a No-Toil Fast Filter (pre oiled) for $15 at cycle gear. I can't imagine that the stock filter is any good at this point and time, especially if the bike was stored out side.
You seem to be describing a air delivery problem, since the carb was replaced and it didn't go away, move to the air box and the carb boots on both ends need to be checked for proper sealing and cracks (check for mice nests, if you didn't already).
newbbewb wrote:^what he said.
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tommy1
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2001 220R with mysterious problem (running rich)

Post by tommy1 »

6 Riders, Thats not a bad idea. All I did to the filter was wash and re-oiling it. The stock filter looks almost new but you never know. Something cheap to try anyway.

One other thing I thought of and forgot to mention is when I turn the crank by hand there is a errrr errrr sound as you turn it back and forth, like a dry seal. I wonder if the right crank seal can be giving problems. Maybe I should try a suction test on the crank case. I did take the magneto off and the left seal is dry. Oil level hasn't moved.

Thank you and keep the comments coming. My aging brain (and bike) needs all the help it can get :hmm:
2001 KDX 220R
2004 Gas Gas EC200
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Re: 2001 220R with mysterious problem (running rich)

Post by 6 Riders »

I thought about the crank seal, but the leakdown held....so I kinda passed on it....I don't know if they effect each other....
newbbewb wrote:^what he said.
masterblaster wrote:Man 6 riders you rock.
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Re: 2001 220R with mysterious problem (running rich)

Post by Jim B »

What two stroke oil are you using?
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2001 220R with mysterious problem (running rich)

Post by MarioM3 »

I believe this could cause a rich condition, if the rings didn't seat correctly. And you just replaced piston, not saying you did anything incorrectly, just throwing some ideas out.

Mario
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2001 220R with mysterious problem (running rich)

Post by tommy1 »

Amsoil Dominator

I think they seated. have 155 psi compression.

I think my next step will be to try spraying carb cleaner on crank seals while its running and see if the rpm raises. I dont know the bikes full history so it could have a bent crank (worst case scenario), or crank bearing/seal may have been installed wrong from factory. or possible a bearing has rust. The link down test looked good but when its running then the seal may not be holding.

I may end up opening the cases and replace the bearings and seals and see how it runs then. Not to costly but a lot of work :rolleyes:

Got a race this weekend I wanted to ride the KDX in but I guess the tried and true Gas Gas will have to do :supz:
2001 KDX 220R
2004 Gas Gas EC200
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2001 220R with mysterious problem (running rich)

Post by canamfan »

You have good compression and no leak down, so I wouldn't start replacing things that aren't bad. I always stay with the basics fuel, air and spark. Of course there can be variable in each of those. It sounds like a fuel air problem so I would concentrate on that. You do have a good strong spark I assume. On that stock carb did you change the jets to known good ones. People have been known to ream out jets so they are not always what the lettering on them says they are. If you have the float height correct and good jets you might try running a bit without the aircleaner to see what difference that makes. good luck.
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Re: 2001 220R with mysterious problem (running rich)

Post by Julien D »

Tell us about this "carb rebuild kit". I have never seen one that wasn't chinese rubbish. What parts were in the kit and where did you get it? When you cleaned the carb, did you soak or dip it? Check the jet block gasket!
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2001 220R with mysterious problem (running rich)

Post by Tioli »

Not saying this is the problem but it can mess with how it idles.

Check your throttle cable free length. If your idle speed is set by half throttle screw and half tension from the cable it can sort of be right but not right and do some of the stuff you discribe.

Do you know where your timing is set? If it's full retard it may leave more deposits.
2001 KX125 with a 1997 KDX Tioli Hp motor

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http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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Re: 2001 220R with mysterious problem (running rich)

Post by Jaguar »

what plug are you using?
do you know how to jet a carb?
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tommy1
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2001 220R with mysterious problem (running rich)

Post by tommy1 »

Spark plug is BR8ES. I put a new spark plug each time I tried different jetting. (got a lot a spares now). Also tried a Dodge 318 spark plug. gap .3 to .32

Jetting is close as I could (starting with main jet and working down to idle jet/screw) with the original carb which ended with the jetting noted in my 1st post. Jetting on the 200 carb I guessed at but should be close. Since the symptoms are the same with the carb change makes me think its something else.

Throttle cable has its free play. I can adjust idle with the idle screw with no throttle cable interference.

Carb rebuild kit came from JetsAreUS.com . I've used them before and the gaskets look decent. Got to remember, symptoms are the same with two different carbs.

Jets i've been using I have had for a long time and trust. There are also new ones in the bunch (never needed the real lean ones before).

Lots of suggestions, Thanks! I don't mind being asked to check something I already checked. I may have missed that one thing. It will be next weekend before I can check the crank seals again (thats my next step after putting a rear tire back on, I had to use the one off the KDX when I found my rear tire flat (broke valve stem) on my gasgas just before a race yesterday). From there i'll recheck the reeds/intake then start looking at electrical again.

Thank you all for your comments and suggestions. Keep them coming.

Cheers
2001 KDX 220R
2004 Gas Gas EC200
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2001 220R with mysterious problem (running rich)

Post by Tioli »

You discribe and suspect rich mixture so let's follow that thought.

If it's to rich it can only to much fuel or not enough air.

Air leeks anywhere in the inlet trac or seals are going to give you lean as it's additional air so let's put that thought on hold for now.

Not enough air is a blocked passage so it will draw more fuel. Both pilot and main jet are air fed to create an emulsion before it entrees the carburettor boar. Restrict that system and you get rich.

Symptoms sound a little pilot jetish. You never said where your pilot air jet is set at? The passage may be clean when all parts are removed but screwed in to tight.

Personally I like to strip carbs of every thing brass, clean my carbs then run them under water and blow it out with a air gun. That way I can target every passage forward and back and watch it blow water out every passage to my satisfaction. The pilot passages will have about 4 exits block 2 off with your fingers and blow water out the target one,repeate for every exit.

To much fuel is not enough air. I don't have a 220 but believe they have lower height exhaust and side ports plus restricted inlet bridge ports. This setting is for more power at lower revs and less top end. It will not want 200 fuel ratios so dint think it wants one. ? 220 have smaller carbs so is the rubber reed block mount smaller inside to match?

Roughly with overlap. Pilot to 1/4, needle to 1/2 then main jet.

You start jetting from pilot and get that sorted as it won't matter what size main you have till after 1/2 throttle (in theory).

Small carbs (220) are drawn harder across the rev range so are more efficient at atomising your fuel. Bigger carbs will give you more top end air at the expense of low rev atomising efficiency. That's why the RB splitter plate is so good, big and small all in one.

Make it run at low revs like you want first. The top end is a very wide setting as most play in the mid range where the main jet is barely in play.

I have done a lot of plug chops in my time, full throttle down the main straight on motors that live to rev.

How do you plug chop a trail bike that will never see those conditions? My guess is to ride it how you do for a while then just stop and have a look. Don't let it idle, drive up the drive when you get home etc. half way through your ride clutch in and hit the killswitch and have a look

I jet by ear.
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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220 with mysterious problem (running rich) -Problem solved

Post by tommy1 »

Its been a few months but have finally figured out the problem. I have read hundreds of posts on the internet, taken the carb off the bike more times than I can count trying different jetting and have tested and/or replaced many items on the bike trying to figure out the issue. I write this in hopes to help others who find them self's in the same dilemma. It seems you can always find the "its broke, how do I fix it" post on the internet but no one ever finalizes the thread by telling what cured the issues/problems they were experiencing.

To sum it up it was the carbs. Both carbs (the original and used replacement) were bad. The last test ride I had I noticed it was always on decel, down hill & braking sections that the major problems would occur (major problems being, loading up, low idle, dieing, fouling plugs). So I let the bike idle stabilize then rolled down a very slight slope in neutral and when I applied the brakes the idle would drop. That to me indicated a carb problem (fuel dumping down its throat). When I mentioned this to my brother (who is a MMI trained tech with 25 years in the business) he told me of a bike they once had an issue with that the manufacturer gave him grief over trying to get a carb replaced on warranty because it had a porous casting. Turns out both the carbs I have had that problem and would let fuel bleed through the casting and of course affect the fuel to air ratios. I went a head and ordered a new 35mm keihin carb and the bike now runs great.

With the bad cards I was having to run 35/136 jetting to get it close. with the new carb I am currently at 42/160 (which is real close to where it should be) and the bike idles fine with no loading up or fouling of plugs.

After countless hours....Finally..................fixed :boogie:
So if you are ever having issues running rich and having to run extremely small jetting to get your bike to run you might try a new carb.



:partyman:
Last edited by tommy1 on 06:39 am Aug 11 2016, edited 1 time in total.
2001 KDX 220R
2004 Gas Gas EC200
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2001 220R with mysterious problem (running rich)

Post by Puppacharlie »

I have a 2001 KDX220R that has been running rich since new. It has a #35 pilot Jet and the needle clip is in the leanest position.
It idles perfect with no stalling and it no longer fouls out the plugs. The problem is that it runs rich right off idle through about quarter throttle,
Do you think this could be a bad carb as well?
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