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float level setting

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I adjusted my floats this weekend and I'm not sure where this diagram is measuring from but there's no way to get 16mm. Max float drop is only about 13. Where the valve seats is in the 8mm to 10mm range and that's with the seam on the floats a little below the bottom flange.

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Just take your carb off, remove the float bowl, put a 1 foot long piece of fuel line on the carb's fuel inlet. Hold the carb upright and then blow into the hose. Start pushing up on the floats until you can't blow though the hose any more. At that point, note the relation of the floats to the bottom of the carb.

Remove the floats and bend the tab just a little...install and repeat the above procedure until the floats are ~2mm lower. It will take a few times to get it right.

Note how the left edge of the float seam is aligned with the bottom left side of the carb...this is where you want it.

bild2.jpg

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goodness guys, you over thinking this and stuck with these measurements. Its not that big a deal, just bend it some and ride it, its that easy.

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goodness guys, you over thinking this and stuck with these measurements. Its not that big a deal, just bend it some and ride it, its that easy.

If you are going to go through the trouble of removing the carb, you should at least know where to set the floats. If you just bend the tab willy nilly, you may still be too rich or worse yet it might be too lean. My procedure takes no more than five minutes once the carb is off......far from over thinking the procedure.

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my eye is my measure, been doing it for 0ver 40 yrs, always works, never failed. To each his own. Its not a complicated thing to do for sure either way. I was commenting on the guys who dont seem to get it, you were trying to explain further and I wasnt commenting on your post, just the whole idea that this is a technical adjustment when it really is not.

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The one thing that was asked and wasn't answered is "what is the float height?"

For the FLAT TOP carbs with the Allen screws the float adjustment is 6.5 MM. Same as the PWM carb model.

I also suggest lowering the floats 2 MM or to 8.5 MM. Do NOT exceed 9 MM.

For the older round screw cap carbs float height is 16 MM and again I suggest drop 2 MM to 18 MM.

Despite Mike's 40 years experience, float height IS critical and DOES matter. I'm not getting into the reasons here. Fully discussed on KTMtalk but unfortunately buried in an older thread.

Follow Gary's advice and link on how to PROPERLY set float level.

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Just take your carb off, remove the float bowl, put a 1 foot long piece of fuel line on the carb's fuel inlet. Hold the carb upright and then blow into the hose. Start pushing up on the floats until you can't blow though the hose any more. At that point, note the relation of the floats to the bottom of the carb.

Remove the floats and bend the tab just a little...install and repeat the above procedure until the floats are ~2mm lower. It will take a few times to get it right.

Note how the left edge of the float seam is aligned with the bottom left side of the carb...this is where you want it.

bild2.jpg

Perfect. Thanks! yeah, 16mm for this carb isn't possible. Thanks for clearing that up.

A measurement is great because adjusting foats trailside on a dirty bike sucks, so does a lean condition.

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Before you change the floats do this!!!!

Check and make sure when the bike is vertical the carb is vertical. Mine was tilted to the side about 10 degrees. KTM doesn't key the carb like I've seen on other bikes. You do have to pull the tail section and airbox but that ain't a big deal.

Fixed that and my dribbles went away.

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Yes Jersey, you too are very knowledgable in jetting, it does matter, but its so easy to do and eyeball, its not that "Technical", maybe that is a better word for it.

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Mike, yes I agree it's not very technical or difficult. I generally set them by eye myself. However what's easy and done without much thought for those that have been doing it for a while, you need to remember not everyone is as mechanically inclined as you and for those doing it for the first time. There is a specific factory setting and that's what was asked. That info on the flat top is not that readily available for KTM's. It is also critical that the spring loaded plunger not be depressed. In a manner of speaking it is somewhat technical. Technically there is not a setting range, if there was the factory would specify. However because of the mounting position, it is safe to drop 2 MM. To go much farther runs the possibility of running the fuel bowl dry or suck air under certain conditions.

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Just take your carb off, remove the float bowl, put a 1 foot long piece of fuel line on the carb's fuel inlet. Hold the carb upright and then blow into the hose. Start pushing up on the floats until you can't blow though the hose any more. At that point, note the relation of the floats to the bottom of the carb. Remove the floats and bend the tab just a little...install and repeat the above procedure until the floats are ~2mm lower. It will take a few times to get it right.Note how the left edge of the float seam is aligned with the bottom left side of the carb...this is where you want it.bild2.jpg

Bringing this one back form then dead. Thanks cactus this worked great on my 12 xc300 it was dribbling real bad but not any more

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That's funny, I just saw this thread and clicked on it without realizing I started it 3 years ago.  I've been sharing this with people ever since.  I just got a 2014 250xc and needed to do the same procedure. 

 

It may add value to say I used a dentist's (tooth scraper) tool to bend the tab.  That way you don't need to keep removing the pin and floats.  Handy tool if you can round one up from your dentist.  It works for cleaning gaskets, grooves, threads, pulling o-rings too.  

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Just take your carb off, remove the float bowl, put a 1 foot long piece of fuel line on the carb's fuel inlet. Hold the carb upright and then blow into the hose. Start pushing up on the floats until you can't blow though the hose any more. At that point, note the relation of the floats to the bottom of the carb.

Remove the floats and bend the tab just a little...install and repeat the above procedure until the floats are ~2mm lower. It will take a few times to get it right.

Note how the left edge of the float seam is aligned with the bottom left side of the carb...this is where you want it.

bild2.jpg

This is an older thread.  Anybody in recent time check their float level and adjust it to this much of an angle? Manual says level, or max +1 degree. I have a 2013.

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I have adjusted all of my KTM's two strokes using this method...'06, '08, '10, and '13. If you adjust it as the manual states, it will be too high. 

Float height.jpg

Edited by Cactus73

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On 3/18/2011 at 1:00 PM, alwho44 said:

Before you change the floats do this!!!!

Check and make sure when the bike is vertical the carb is vertical. Mine was tilted to the side about 10 degrees. KTM doesn't key the carb like I've seen on other bikes. You do have to pull the tail section and airbox but that ain't a big deal.

Fixed that and my dribbles went away.

This ^ this is important! With the bike on a center stand I use this small line level. As you can see I route my vent lines to the front of the carb. No particular reason. I just feel they are more out of the way, but it does allow me to place the level on the back side. It is the perfect width for the tangs to catch the outer screws of the carb. I just did this with the airbox on and it's really not that difficult. But it does make sure that sucker is level. I was surprised how far off it was, even with my trained eyeball. Lol. 

38mm pwk on 300.jpg

Edited by thefullmonte

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