Kawasaki Kx250f 2016
Arabella Kochanski
I've got a 2007 kx250f that keeps leaking coolant from the overflow tube. I've replaced the radiator cap thinking it was just that because the old one was so weak, but it didn't solve my problem. I put the coolant just above the fins inside the radiator to allow for expansion like it recommends but it still leaks quite a bit, I didn't know if you had to purge the system somehow to get all the air out or if this could somehow be a head gasket problem. Thanks
By nature the system bleeds out air automatically when the engine is running. When is it leaking? Is it excessive idling or not riding fast enough to get air moving through the radiators? If its not user error then check the water pump for issues as stated above.
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Thanks for the responses, I'll look into it as soon as I can, I just rode all day with no noticeable heat issues, but it seams to leak when it just gets warmed up then periodically after that, it's only like 2 or 3 tablespoons everytime, but after awhile, like 3 or 4 hours of riding it gets pretty significant.
As GasMixer44 mentioned, letting the bike idle too long is bound to make this happen. Similarly, if you putt around the trails or track too slowly, you'll see this start to spill out (this has happened to me a couple of times). Getting on the gas to get the air moving should really help. In general, if it's only leaking while it's on I would most likely suspect something is making your engine run too hot and you're just not getting enough air to cool it off.
Fwiw, I notice on my 2t that I can let the thing idle and have almost no heating issues; I never had coolant overflow on it. On my 4t though, I never let it sit more than a minute before getting a move on. If on the trail and we stop, the bike gets shut off until we're ready to move again.
TO check the head gasket, pull radiator cap, start bike, and look for bubbles in coolant. I doubt this is your problem because a blown HG typically creates a chronic overheating problem, ESPECIALLY IN THESE BIKES.
Also, for the record, running less EG, and more water in the coolant mix, I prefer 70% water/30% EG, creates a more efficient system. This is where the water wetter really comes in handy. It really makes the water work better at removing heat from the engine and putting it into the radiators. In the place where I live, Las Vegas, I could probably run 100% water and see great results, but I do go to places where it gets cold at night.
Anytime I bring up the whole water thing, usually the backlash is huge and people just go off. It works though. And I don't see the advantage of using 50 50 coolant unless you live in Alaska and ride in the winter. Water simply cools better, when water wetter is used...
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I just purchased a 2007 Kawasaki KX250F in pretty good condition. The previous owner said it was serviced regularily. I went out riding for my first time and noticed it was leaking oil out the black brether hose. I changed the oil but it still seems to still leak oil. Does anyone know how I can fix this problem?
Only time i've ever seen oil blowing out the tubes on a 250f is when the cylinder is worn or scored. Allows blow by pressurizing bottom end, which carries the oil out the tube as more air is flowing out of the tube than usual. I used a mildly scored cylinder on my 11 250f in a pinch and it started blowing oil out the breather the first ride with that cylinder. Replaced with new cylinder problem fixed.
This is a very common problem with 07 kx250f , do a search. We have one we run the oil at the bottom of the sight glass, it seems to blow less oil that way. When you change your oil if you put in the full amount they will often blow a lot of oil on start up. The secret is to put in only about 750 cc run it for a minute or so then add another 250 cc this should get it to the bottom of the glass. A lot of people have rebuilt these motors thinking they had a problem only to have it happen again. The vent hose is too close to the clutch which picks up oil and throws it out.
I have searched and performed almost everything I have seen on here but I am still having the same issue. Bought this bike a week ago. It started up with choke only and when you take the choke off it instantly dies. I have tried three different pilot jets as everyone has indicated that is the problem. I tried a #52, #40 then a #45. Bike runs about the same with any of the pilot jets in it. Cleaned the tank and put a inline fuel filter to make sure no sediments are getting into the carb. I have taken the carb apart 4 times very meticulous about cleaning every little jet and also making sure the float bowl is in spec as well. I threw a rebuild kit in and changed all the o rings and screws as well. Checked all the air intake hoses for leaks, brand new oiled air filter as well. I am hitting by head against the wall right now trying to figure out what it is! PLEASE HELP!!! BTW I am in Arizona where the elevation is about 2300ft. Bike starts easy and seems to runs fine with the choke on but obviously something is not correct for it to not idle with the choke off.
Yes I have cleaned out the fuel passage ways every time I have taken it apart. Its possible some junk is still in there but i highly doubt it. Also I rethreaded the hot start plunger so it is in the carb pretty snug.
Without knowing the condition of the engine but assuming the carb is fine based on what you've already done, I'm going to guess you have an air (vacuum) leak or there's a cylinder issue, either valves or rings. A compression test and vacuum test would help know more.
Okay so I took the FCR carb from my 04 Honda crf250 and put it on my kawasaki. Thing started right up and ran great. So then I took the jets out of my Honda carb and put it in the Kawasaki carb. Thing started up on choke but then wouldn't idle again. Needle clip and float level are exactly the same from carb to carb. Is there an internal problem with the carb to not make it idle? I'm so lost here!
Hey guys, I know this topic is a couple years old, but I have the same issue going on here, and I got a complete new carb. I should probably tell you I fix dirtbikes for a living, so it's not often I get stumped like this. Bike runs good on choke, kinda like it's not really on choke, but as soon as you shut choke off it won't idle, or even stay running unless you are giving it the juice. Cleaned carb about 4x's, put everything to OEM spec, rebuilt carb top to bottom, than finally got a new carb, jetted it to OEM spec with brand new jets. Still the same, the valves were very tight, I did reshim those, compression is good, leak down test passed, it's probably not far off from a rebuild, but it should run. Cleaned tank and petcock, new air filter and cleaned intake boot, new spark plug, I have the hotstart cable unhooked to be sure it's returning, which bike runs with that pushed in also. Any ideas would be helpful, I'm going to mess with this hotstart a little more, but it's brand new, don't feel like it could be leaking.
Ebay was all we could find, OEM wasn't available, carb appeared exactly identical besides the hot start being vertical instead of horizontal, and it came with a 135 main, 55 pilot, which I changed to the OEM sizes of 182 main 40 pilot I believe, needle 2nd position from top, air screw 2-1/4 out
This bike came in because it was leaking oil and gas, I wish I would have started it first to see how it ran, I just changed seals and rebuilt carb, than started it, it doesn't leak oil or gas, but it doesn't idle either and I have no idea if that was the case previously or if it was something I did, I can't get any feedback from the owners yet.
If it runs good but won't idle, what have you got the idle adjustment screw set to? These bikes it's super easy to adjust. Also what's your fuel screw set to? Post a photo of the carb installed I want to check something, both from left and right side if you can.
Ok so I know this question has probably been brought up a million times but id like to hear some answers for myself. I just bought a 2005 kx250f and I'm wondering what kind of oil to run in it? I've had other four strokes in the past but every bike is different. Id also like to do some routine maintenance on it the bike... What should be done? The bike is in good shape and looks to be well taken care of but being that I just bought it I'd like to freshen it up. Another thing I've been wondering the transmission clutch and engine oil is all the same right? I appreciate any feed back, ill be doing the work myself would just like to hear it from some guys who have more experience with these bikes. Thanks
It is odd how this version of the manual recommends Castrol 'R4 Superbike' 5W-40 oil one place, and then recommends 10W-30, 10W-40, 10W-50 in the viscosity table. I have never run a 5 weight oil in my bike, but I guess it might be a good choice in cold weather riding. I usually run 10W-40 and I am thinking of trying some of the synthetic Rotella blue bottle stuff that is 5W-40. That should be an affordable oil that is high quality. However I have some minor concerns about diesel oil because in general a diesel engine does not rev very high, and obviously a 250F does. I think 6000 RPM is redline on most truck diesel motors. Even car diesel engines like in a volkswagon or volvo don't rev too high. So, if there is not a anti-foaming additive in the oil for high RPM operation, it may not be the best oil to use. Nobody has reported anything but good protection with the Rotella so I bet it is not a real issue. Just a thought I had...
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