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Hi guys I'm on a 2014 xcw 300. I'll start from the beginning as the problem seems to have gotten worse. It started with having to change the spark plug pretty much every ride. The plugs where always wet and covered in oil (until recently I was using not the greatest quality oil at 1:50 instead of 1:60 that ktm recommends) I figured that's what was killing the plugs so often. This is my first 2 stroke and it took me a while to get into the habit of turning off the petcock so the bike was almost always flooded so I'd have to do the standard deflooding tricks. fuel off, empty carb, kick with throttle wide open, kick with spark plug out to clear fuel out the crank case etc.

 

So I ended up having to do all of this the night before a race and eventually managed to get it started and it seemed to be running well again. Towards the end of my first lap the next day (it was an enduro so about 2 hours in of working the bike hard) it felt like the spark plug died again, I put it in that morning so it was brand new. So I sat there and did all the deflooding tricks again and went through 4 different spark plugs (1 of them brand new) the bike would start but die again very quickly if I let off the throttle and then not start again. When I put the brand new one in it started first kick but the first half of the throttle had no response, it only revved when it was wide open and died again very quickly when I let off the throttle.

 

While switching out the plugs I noticed one of them where still dry which worried me a bit.

 

What steps would you take to try diagnose the problem? I thought maybe the float is stuck therefore constantly flooding but the dry plugs seem to suggest something else. Maybe the starter motor? I've heard the 2014 ktm 2 strokes don't have the best starter motors and a coil could be blown but would that not mean the bike shouldn't start at all?

 

Thanks guys keen to hear what you have to say.

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If it were the starter motor, the bike would have a hard time turning over or not turn over at all. Do you ever have to kick start it?  

As far as a dry plug, it should not be wet. What your looking for on a plug is the color. Should be a nice chocolate brown at the electrode. If it is black, that means it running to rich, and if it lighter your running lean. 

 I would check the compression, from reading a different add, it should be close to about 180psi. If it's close then it should be fine. There is also a bottom end leak check kit, it's a bit expensive but worth it, or see if someone can leak check it for you. If the oil side crank seal is leaking it could also cause your bike to have a rich reading on the plug, and smoke a lot. Just my 2 cents

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Before doing anything correct the floats, the floats job is to shut the fuel off at a preset fuel height in the carburetor bowl.

You're floats are malfunctioning or out of adjustment causing fuel to pass through the carb and into the engine, you should not "Have To" turn the pet cock off, correct this before moving on, this is probably you're main issue

Edited by gitenby

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Are you the original owner? Or did you buy it used and have just been running it the way you bought it?

What's your elevation and current jetting?

Have you ever had the carb off or apart?

Have you checked the reeds?

Be sure you're using the right plug and heat range and it's gapped properly.

300s don't foul plugs very often and certainly not like you're doing unless something is seriously outta whack.

We need more info.

And getting into the habit of turning off the petcock is good. Extreme swings of atmospheric pressure changes while stored as well as hauling the bike around in the truck is enough to flood the carb and engine with the petcock left on.

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Sounds like your float valve is leaking if you have to turn off the petcock all the time. You should not have to do that except when trailering the bike. It may simply have crud from the tank or from the fuel line stuck in it. I mention the fuel line because the original fuel line on my bike disintegrated on the inside and was putting little pieces of rubber in the fuel bowl (and one time clogged the main jet which is when I discovered the problem). I am surprised, though, that you didn't mention fuel running out the carb overflow and onto the floor.  Are all your carb vent lines clear?

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23 hours ago, bruce420 said:

 

Hi guys I'm on a 2014 xcw 300. I'll start from the beginning as the problem seems to have gotten worse. It started with having to change the spark plug pretty much every ride. The plugs where always wet and covered in oil (until recently I was using not the greatest quality oil at 1:50 instead of 1:60 that ktm recommends) I figured that's what was killing the plugs so often. This is my first 2 stroke and it took me a while to get into the habit of turning off the petcock so the bike was almost always flooded so I'd have to do the standard deflooding tricks. fuel off, empty carb, kick with throttle wide open, kick with spark plug out to clear fuel out the crank case etc.

 

So I ended up having to do all of this the night before a race and eventually managed to get it started and it seemed to be running well again. Towards the end of my first lap the next day (it was an enduro so about 2 hours in of working the bike hard) it felt like the spark plug died again, I put it in that morning so it was brand new. So I sat there and did all the deflooding tricks again and went through 4 different spark plugs (1 of them brand new) the bike would start but die again very quickly if I let off the throttle and then not start again. When I put the brand new one in it started first kick but the first half of the throttle had no response, it only revved when it was wide open and died again very quickly when I let off the throttle.

 

While switching out the plugs I noticed one of them where still dry which worried me a bit.

 

What steps would you take to try diagnose the problem? I thought maybe the float is stuck therefore constantly flooding but the dry plugs seem to suggest something else. Maybe the starter motor? I've heard the 2014 ktm 2 strokes don't have the best starter motors and a coil could be blown but would that not mean the bike shouldn't start at all?

 

Thanks guys keen to hear what you have to say.

 

What is the jetting at the moment ?

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Your rich on the needle 
 



Try a different needle or change the position? By rich do you mean it's letting too much fuel out? Bare with me, I'm new on the whole jetting thing


Sent from my Redmi 4A using ThumperTalk mobile app

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Are you the original owner? Or did you buy it used and have just been running it the way you bought it?
What's your elevation and current jetting?
Have you ever had the carb off or apart?
Have you checked the reeds?
Be sure you're using the right plug and heat range and it's gapped properly.
300s don't foul plugs very often and certainly not like you're doing unless something is seriously outta whack.
We need more info.
And getting into the habit of turning off the petcock is good. Extreme swings of atmospheric pressure changes while stored as well as hauling the bike around in the truck is enough to flood the carb and engine with the petcock left on.


I got it used and have been running it the same, the jetting is the same as how the bike came

168 mj
35 ij
N4DJ needle 4th pos

I live in Cape Town, South Africa so am usually riding between 0 and 500m

I did take the carb apart to clean it, possibly didnt the put the float back perfectly


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6 minutes ago, bruce420 said:

 

 


Try a different needle or change the position? By rich do you mean it's letting too much fuel out? Bare with me, I'm new on the whole jetting thing


Sent from my Redmi 4A using ThumperTalk mobile app
 

 

 

Try clip 3 ( middle ) , look into the Suzuki triple taper needles , pm me if you like

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Before doing anything correct the floats, the floats job is to shut the fuel off at a preset fuel height in the carburetor bowl.
You're floats are malfunctioning or out of adjustment causing fuel to pass through the carb and into the engine, you should not "Have To" turn the pet cock off, correct this before moving on, this is probably you're main issue




Sounds like your float valve is leaking if you have to turn off the petcock all the time. You should not have to do that except when trailering the bike. It may simply have crud from the tank or from the fuel line stuck in it. I mention the fuel line because the original fuel line on my bike disintegrated on the inside and was putting little pieces of rubber in the fuel bowl (and one time clogged the main jet which is when I discovered the problem). I am surprised, though, that you didn't mention fuel running out the carb overflow and onto the floor.  Are all your carb vent lines clear?


Iv taken the carb out and checked the float, it doesn't seem to be getting stuck and the needle is in good condition. The measurement from the top of the float to the start of the bowl is 14mm should that distance be increased?. Should I be looking for anything else in the carb? I've cleaned jets etc

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Has it ever run good with you? I'm not familiar with the jetting sizes on your bike, someone else needs to tell you a starting point of just use the service manual to get it.

Go after the basics and verify the PO didn't wack out the jetting. Every bike is jetted differently, you get the starting point and go from there. Google jetting a 2 stroke and learn the art of jetting.

When I get a used bike I typically go through it with a fine tooth comb, don't even take the plug for granted, he may have put the wrong plug in it.

Build a leak tester, it's your best friend when you have a 2 stroke, look on the Honda 2t forum (pinned)  for directions how to build one.

you have a great bike and very easy to work on, some day I'd like to get back to a 2t

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If gas is not running out of the overflow on the carb when the bike is at rest your float is probably OK.  To me it sounds like your ignition may be acting up.  I have never known a modern 300 to foul a plug unless it had a weak ignition.  

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On 8/30/2017 at 5:56 PM, bruce420 said:

 

When I put the brand new one in it started first kick but the first half of the throttle had no response, it only revved when it was wide open and died again very quickly when I let off the throttle.

 

 

I would say this is a blocked pilot jet, had this on one of mine, same symptoms. Did you pull the jets and clean/blow out all the jets/galleries/tubes out while it was apart?

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Thanks for all the input guys. For those of you interested, it was the reed valve. I've also gone leaner on the premix and jetting. Bike is running like a dream again. IMG_20170902_144828.jpg

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