leaking overflow/float level

kdxdazz · Post by **kdxdazz** » 11:16 am Jan 01 2018

still trying to sort out this poorly treated KDX220. i adjusted the float level to 17mm as it was previously set at 20mm,since i did that it will overflow from the carb at the slightest lean angle,the pilot jet is a 38 and setting the fuel screw at 4 turns out does not make it stall,it smokes alot at idle and has lots of spooge,if you turn off the fuel tap it runs a bit better and stops smoking until it runs out of fuel,anybody have experience setting float levels that are ouside of the normal range, i have a feeling the carb is a chinese PWK copy

jackbombay · Post by **jackbombay** » 12:14 pm Jan 01 2018

You might have a bad jet block o-ring, does it ride decently? But only "loads up" and runs rich if you let it idle for more than a few seconds? If so, I would start with the jet block o-ring. Its not actually a circle, it's a crescent shaped seal, a couple of tiny torx screws inside the carb need to be removed to replace it.

Post by **KDXGarage** » 02:27 pm Jan 01 2018

Security Torx

kdxdazz · Post by **kdxdazz** » 09:21 pm Jan 01 2018

jackbombay wrote:You might have a bad jet block o-ring, does it ride decently? But only "loads up" and runs rich if you let it idle for more than a few seconds? If so, I would start with the jet block o-ring. Its not actually a circle, it's a crescent shaped seal, a couple of tiny torx screws inside the carb need to be removed to replace it.

i will keep that in mind thank you,it does ride ok but the jetting is not even close so hard to know how well it rides. the carb i think is a fairly new copy so there shouldn't be any worn parts. i tried 3 methods of setting the float level,first one was calipers to set at 16mm, second was checking it was parallel by eye and third was blowing down the fuel pipe until the float closed off the supply and was parallel . service manual says 16mm plus or minus 2mm so might drop it down to 18mm and see if that helps

Kdxjarret · Post by **Kdxjarret** » 09:17 am Jan 02 2018

Sounds a lot like what my bike is doing.... I couldn't get it lean enough. I ordered a jet block o-ring and rebuild kit last week. I hope to have it out back together later this week. I will give an update on if that is the problem. Several members on here have told me it's a good idea to change jet block o-ring just to rule it out so took their advice!

ohgood · Post by **ohgood** » 12:46 pm Jan 02 2018

kdxdazz wrote:still trying to sort out this poorly treated KDX220. i adjusted the float level to 17mm as it was previously set at 20mm,since i did that it will overflow from the carb at the slightest lean angle,the pilot jet is a 38 and setting the fuel screw at 4 turns out does not make it stall,it smokes alot at idle and has lots of spooge,if you turn off the fuel tap it runs a bit better and stops smoking until it runs out of fuel,anybody have experience setting float levels that are ouside of the normal range, i have a feeling the carb is a chinese PWK copy

turning the mixture screw out well not stall the bike. turning it in will.

if you can't hear distances at the a air screw adjustments, you have a jet block gasket problem.

38 is too lean.

kdxdazz · Post by **kdxdazz** » 08:35 pm Jan 03 2018

pulled the carb out again,double checked the float level and it was more like 16.5mm,thats touching the rod but not depressing it,set it to 17.5mm and the leaking overflow is fixed,bike is running leaner now and not blowing so much smoke but still seems rich. forgot to take a flat head screwdriver with me so couldn't check the fuel screw,i set it at 2 turns out before i went up to the mountain. not sure if 38 is too lean or not,as i went up the mountain gaining altitude the bike would stall at idle . i'm in the north of thailand here so with the heat,humidity and altitude combined bikes need to be jetted leaner. the bike still has a lot of spooge but is running acceptable to the point where i might put my wideband 02 sensor in soon and take some readings. while on the topic anybody know best AFR's for 2 strokes

david · Post by **david** » 09:21 am Jan 04 2018

Just for the record....it's an air screw, not a fuel screw. Turning it out adds air to the fuel stream.

17.5mm is where I had to set my float to get the needle to seat properly too.

kdxdazz · Post by **kdxdazz** » 02:16 am Jan 09 2018

thought i would post as this may help somebody with float level setting,on my carb i set the float using two methods,first was measuring the float height,i had that set at 17.5mm and my bike was still running super rich. checked using the service method as described in the manual with the clear tube. it was showing 2mm above the float bowl mating service. goes to show you cannot just measure the float height as it is not accurate and doesn't allow for possible deformaties of the actual float

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