On-going KDS Bog Problem

[Pwgsx]

ok, after adjusting the floats and cleaning the jets, I re-installed everything and the bike started right up. HOWEVER .........it is still acting up!!!!! Here is the story.............
It idles great but even in neutral, when I give the throttle a few twists, it BOGS way down and sometimes dies. I shut the fuel valve off after I was trying to restart the bike b/c it seemed flooded. When it finally turned over and ran, I revved the engine for a while and it seemed to be getting better with no bog. The engine finally died again b/c the carb ran out of gas b/c the valve was off. Becasue of the leaning gas in the carb and the engine running like it should, does this sound like a jetting problem????? I have no clue what the jetting is but im assuming its stock. I dont know much on adusting carbs except for the idle and air screw. Any pics, or diagrams would help.

I am all out of ideas....... So far I have checked all wires, installed a new plug, replaced the stator, replaced CDI box (per the guy at the shop suggested) ,adjusted float level, check fuel valve for clogs, replaced fuel line, cleaned the carb and today I took off the KIPS cover and there was a lot of black oil and black gunk inside. The valve was moving freely but I cleaned it anyway. The exhaust is spitting out black oil. The only thing left to replace is the ignition coil. Any Ideas and HELP would be appreciated!!!!

 

[G. Gearloose]

Sounds like a fouled plug due to sloppy jetting.

 

[John Cena]

Definatly sounds like its running rich and messing up your plugs. What spark plug heat range you running?

 

[Pwgsx]

The plugs are what comes standard on the kdx 200. Im not sure of the number but i checked them and its correct. they r really fouled but until I correct the problem, new plugs get fouled in one run down the street.

Does any one know the proper jetting\????

 

[cyber104]

I always have to ask...are you SURE the choke is not on or stuck on?

 

[Colorado Mike]

Sounds like you're all over the place on stuff you have tried. You need to be systematic about troubleshooting the thing. First off, Did this bike ever run right since you bought it? If not it could be a lot of things. For example I once had a retard mechanic put the wrong size piston in one of my race bikes. It would start but run terrible at low rpm, took like 20 seconds to clear out, then it would run pretty good at high rpm. I'm not saying that's your problem, just illustrating how a lot of things can mimic a carb problem. You don't say what jets are in your bike now or what happened just before it started running bad. swapping all these parts could have introduced a problem too. If one of your buddies have a similar bike you could swap carbs to see if the problem moves.

Good Luck,
Mike.

 

[Rhodester]

Check for: Needle and seat not seating tight, float sinking (leak in float), choke stuck on, gas able to free flow with gas line to carb off and flowing into a container, try running with and without air box lid, dirty air filter (try running with no filter for a couple of minutes to see how it runs), intake obstruction, exhaust obstruction, try new fuel/premix @ 40:1, try new plug BR8ES or BR8EG, plug wire or boot with crack (sometimes finding a new ground, not spark plug). wet ignition system/parts, Jetting (to start from) 155 main, 45 pilot, air screw 1 1/2 out, needle clip in 2 or 3, vacuum leaks (do a leak down test), pull the top end and clean everything including all KIPS parts, check your grounds and all connectors.

 

[kmccune]

Now I know why no one was helping you. :) I’m with Rhodester put some jets in that should at least make it run and check the float and main seat. Take the air filter ALL the way out and clean/oil it. I once had a mouse build his dream house inside my filter, I had the carb on and off I don't know how many times and from inside the air box everything looked normal. Visually check the spark too.

 

[Pwgsx]

yes, the bike ran fine when i got it. a year later the engine went and was rebuilt and ran fine for months. It all started after riding and I was going back to the truck and I had no power. When i got home i ran it in the street and was bogging like it is soing right now. As for what has been done to correct the problem, came all from ideas from the mechanic thats near me. Nothing has worked and it sucks!! All air ways and fuel lines are clear and gas runs freely. The spark was tested good. A buddie of mine said maybe the Ignition coil is bad and when it warms up, its not producing a correct spark and may be sparadic and is hard to test for. Does that sound like a potential solution???

 

[know_fear]

Yes,both the ignition coil or pick up coil can cause a weak spark after they warm up. Check the color of the spark with a new plug when it's running badly. Ground the plug to the frame or engine with vise grips while you kick it over. If it's not a fat blue spark you have a problem.

 

[cyber104]

Let's start at ground zero. Have you checked the compression? Many folks miss this step and it will provide valuable information.

Chris

 

[Pwgsx]

Ok, I rejetted the carb and needle clip is in the 2nd position. Still the same problem...... I didnt think it was the jets b/c it ran fine before and they have not been touched or changed. The spark is nice and blue when the engine is cold. After it warms up, the plug is black and oil coated. The spark looks weaker though and not that bright blue but it is still sparking. Already replaced CDI and Stator. Must me the ignition coil????

 

[kdxtaz]

Have a leakdown test done. It could be bad crank seals.

 

[Pwgsx]

I checked the jetting and everything seems to be correct. The plug is not oil fowled when it runs correctly in the first 4-5 min. , However, after the problems start, it turns black and oily. It must be a electrical problem with a weak spark. Im replacing the ignition coil this week. Any other ideas?

 

[kmccune]

Hope it works, if it doesn't do a leak down like KDXTAZ says.

 

[Pwgsx]

What exactly is that?? I saw a kit in a moag. but what do you do??

 

[Crazymlh]

I am experiencing a very similar problem with my yz250. All jetting was good and unchanged then out of nowhere comes this bog after a very short running time. Check the carby over and over clean it and adjusted float levels with none of it making a difference. I get a similar result with the spark. I too believe it to be the coil. Keep us posted after you put on your replacement coil.

 

[Pwgsx]

Well I got a coil from a dirt bike salvage yard that was exactly a 1990 kdx. It was only $30 but after installing it, the bike runs, but does the same crap. It's jetted right, floats are great, replaced CDI box, Ignition coil, plug and wire, no clogs in intake, im going to replace the stator one more time. I read somewhere that the Moose stator had some problems. If this doesnt work, its up for sale for $1,000 ! ! !

 

[Pwgsx]

:ugg:

 

[kmccune]

The dealer has always done it for me, as a favor because they knew I was going to buy parts from them, but I have always had good relationships with the local dealers so your experience may vary. They may just charge you labor for the time?

 

[cicone]

I hate to beat a dead horse, but if you replaced your stator coil with an Electrex/Moose coil, that could be the problem. According to Moose, they have a 1 in 4 failure rate under warranty. I went through three in 10 months---and the bike never ran quite right even with freshly installed ones. You say the spark is measurably weaker after the bike warms up---a symptom of a failing coil. Before you give the bike away, check Ricky Stator for C31 coil-- $40 bucks!---half the price and infinitely better quality. IMHO. Good luck.

 

[John Cena]

Do the ricky coils offer any better performances then OEM? Any extra power I can get i'll take :boss:

 

[Pwgsx]

:cool: I got my Ricky Stator coil in and the bike fired up with the first kick. It never ran that good in 9 months. Ricky Stator has my vote. I'll never buy from anyone else. Thanks to all who had ideas and helped. MY Bike is BACK IN ACTION !!! :cool:

 

[kmccune]

glad to hear it. :)

 

[cicone]

:cool: I got my Ricky Stator coil in and the bike fired up with the first kick. It never ran that good in 9 months. Ricky Stator has my vote. I'll never buy from anyone else. Thanks to all who had ideas and helped. MY Bike is BACK IN ACTION !!! :cool:

rock and roll!!! :yeehaw: BTW John---I judge the Ricky coil as good or even better than the original. Pwgsx---Please let us know if this is a long term fix. Hate thinking you went on a wild goose chase like, uh, some other people I know, all because a replacement part was a POS. That sux. Glad you're up and running.