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Dirt Wizard
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No real common to get fuel in the oil on an rfs without it running rough. The waterpump seals can be a little tricky and coolant could get in there, but still not as common as a ktm with the water pump on the bottom end. If your carb was flooding it could get into the engine, but it should run like a dog. Is your oil level increasing?
 

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It runs great to my knowledge, it does bog if I go from no throttle to 100 instantly to the point where it can die sometimes. I've read that has to do with the accelerator pump and I put two o-rings on the piece next to where the throttle cables attach to the carb, but that didn't fix it. Could binding those two pieces with an inelastic wire or something prevent this or will I have to look elsewhere to solve this problem.
 

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Dirt Wizard
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Is acc pump working? Does it give a a good 3 second squirt?
If it dies on initial snap of the throttle it can also be due to a to small of pilot jet.
 

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I took my accelerator pump apart and put it back together and everything seemed to work fine. I have an image of what one side of the carb looks like and also I have a video. It is not three seconds, but everything looks fine to me. When I give it throttle, it is a 0-100%.

 

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Dirt Wizard
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Do you know what size pilot your running? I still think anything under a 48 is to small.
I can't see the jet stream properly sorry. They usually spray for close to 3 seconds and about half a metre out of the carb when there working properly. (which is to much fuel). You may have a different leak down jet or longer pin on your pump diaphram.
 

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Dirt Wizard
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I just had another look at the vid. Is it just spraying a quick mist, less than a second? There suppose to stream out. Is there plenty of fuel in the bowl when your testing it, try waiting 10 seconds in between tests.
 

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I have a size 50 pilot jet, most of the lean bog type issues have gone away. For some reason for the past week my bike has started to overheat very fast to the point where coolant starts coming out of the overflow. I fill it up a little past the fins every time. When it starts to get very hot my bike idles rough and will have dead spots and after about 30 seconds to a minute it will die. I ordered a JD jetting kit and I was hoping that'd solve the issue of the idle. My fuel screw is 2.5 turns out. I have a feeling its most likely the jetting as to why it's running hot, but could it be something else? Maybe I'm overfilling the radiators, but that doesn't explain the bike is idling bad, and mostly idling bad when it is hot. This problem is a recent one only coming up in the past 2 weeks. My coolant is more water than it used to be because I don't have coolant here with me at college. I still smell the coolant though when it comes out of the excess pipe.

Slow jet: 85
Main jet: 172
Idle jet: 50
Pilot air jet: 100
Main air jet: 200
Needle is on the 3rd from the top out of 7, I'm not sure what needle it was, it had a light notch on it under the 7th clip, I'm not sure if that means anything
Fuel screw is at 2.5 turns out
 

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Dirt Wizard
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2-1/2 out on a 50 pilot is probably a bit to rich, but shouldn't overheat due to that. Has it still got the thermostat fitted? Bogging or stalling when hot is usually to rich, clogged air filter or valve clearance is to tight.
Ideal pilot jet setting is to have it bog a little when cold, but not when hot. Most carbs are set up with the circlip close to the middle of the number of grooves or one either side.
 

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I put in the JD jet kit which was
Slow jet: 85
Main jet:172
Idle jet: 42
Pilot air jet: 100
Main air jet: 200
Needle is on the 4th from top, red needle
Fuel screw is 1.125 turns out

I cleaned my air filter, checked my intake valves, I slid the .13mm feeler gauge in and it was able to fit, I guess too tight would mean that the gap is too big, maybe the gap was more than what it should've been but I didn't think they were too loose.

I started up my bike and it ran horribly. It only ran rough on choke then when I'd turn it off it would die, no matter what the idle was set at it wouldn't idle.

I've read some and I think my pilot jet circuit might be blocked. That's just what I've read I'm not sure if that's actually it though. My pilot jet is very clean, brand new.

I've also read something about the spark plug connector going bad, but I'm not sure if that's my problem

Could it be something to do with the float level maybe?
 

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Dirt Wizard
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Possibly, I have never fitted a jd jet kit, but I personally think a 42 is to small for your pilot jet. Those guys do it every day and would have a better idea than me.
I nearly bet if you put the bigger pilot back in it will start and run. I thought they ran 48 pilot jets from factory on the 400's anyway?
Check for vacuum leaks.
I wish I could help you more. Very hard without the bike infront of me.
 

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Ok so yesterday I took the air filter off and it was embarrassingly dirty. I cleaned it and put it back in. Then I was reading some obscure forum and it said to put the plate on the slide with the square side down. I put it in backwards, It matched the shape of the slide so I thought it went in pointed side down. I flipped it and today I cranked it and it seemed to run just fine.

After riding some, when it gets hot the idle isn't fidgety, but it still wants to die. If I leave it idling, it will die after about thirty seconds, even faster when in gear, I'm guessing it's because the friction of the gears. I've read that a new spark connector is a solution to problems like this so I have one ordered, it was only 5 bucks.

There was a significant drop in power in the lower mid area which I'm guessing is something to do with the smaller pilot jet.

I figured out my idle screw was much higher than it needed to be because I had the slide plate upside down.

So I read this other forum and it might be that my stator regulators are bad and when headed up they malfunction: http://www.ktmforums.com/forums/offroad-competition-rfs/32810-05-exc-450-stalling-idle-when-hot-2.html

Or maybe it could be my spark plug connector, which I have a replacement coming in monday.

And if it is a faulty regulator, could I just buy a regulator and not a stator? The stators are 194 while the regulators are around 50.
 

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Full Throttle
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Explain what your plug looks like
http://www.4secondsflat.com/plug_chart.html

If the spark passes this test continue troubleshooting the carb.

hot bike is lean bike

your fuel bowl level could be a problem , test needs to start there first.

1.take carb off boots
2.turn on petcock valve
3.find icecream container and tip out fuel into container(report amount)
4. make sure the fuel bowl is working correctly

your accelerator pump should squirt a stream of fuel, that video looked wrong.
If you give it full throttle slowly, does it stream fuel the same time the cam moves the pump arm ? And does it stream the whole time the cam and arm is levering ?
you need to get that running properly before continuing

the needle on the main jet can cause a bog down if its lowered to far into the main jet.



Go back to the standard idle jet size.Get a can of carby cleaner and compressed air and give that circuit a blow through.
Reset main needle in the main jet to middle position for idle screw test
 

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I took the carb off and fixed the float height and that seemed to fix the stalling issue, I guess I was confused about the bike being hot and stalling because when I hop off the bike it bounces and allows fuel to enter the carb. That solved the stalling 100%. I lowered my needle to the 6th position and it feels much better than before. I haven't tried the 5th or the 7th, but i'm happy to stay with the 6th for now.

When working on the bike recently I accidentally let a wrench touch the positive terminal and the subframe at the same time which heated the wrench and blew a fuse. I didn't realize that for the first few days and the electric start had no response from it. I figured out it was a fuse and I replaced it and now I have power, but not enough to turn on the bike. Is this a sign that my battery is bad and can't push that amperage or what.

I feel happy with the snappy throttle response which mainly has to do with the accelerator pump. What improvements could I look for when changing the accelerator pump. It doesn't bog at all at any point, so what more can I get from changing it now?
 

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Dirt Wizard
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Rig up an earth lead from the battery to one of the bolts that hold the starter in.
If your not bogging, don't touch the accel pump, making it squirt more will only carbon up your plug.
 

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I ended up taking it to the shop after rebuilding it a couple times and we took it to highland park where they did a leakdown test and said I had leakage up to 30% then we took it to a local guy and he said it all looked perfect, I didn't even have to replace the rings on it. I rebuilt it and took it back to highland park and they said it now had a leakdown percentage of 5%, but it still ran like garbage. It was in their hands and they said that some leak purge thing near the cam had been filled with silicon which was probably my fault. I attached the bill for it below. They took out the jd jet kit I put in it and just replaced with stock settings.

The mechanic said to basically sell it while it's running, but we bought the bike for 2800 and have put at least 3k into it. I feel that's not the best investment retrospectively, but I don't know what to take of the mechanics advice. I heard an article recently that they're building cars too good nowadays where they last much longer and don't need as much maintenance so dealerships are losing money. I don't know how well this applies to motorcycles or at all, but it got me thinking. He said the best bike to get would be a newer 350 exc because of its newer valvetrain and overall less maintenance.

I know the ktm rfs line up went from 2000-2007 in motorcycles, then 2008-2011 for the xc4, but what is the engine name that came after that, I can't seem to find it.

I've read many forums on how reliable the rfs engine is and how long it'll last, but would it be best that I sell mine and go for a newer one for the maintenance and reliability or was what he said not really grounded in much truth.
 

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