kawasaki KX 250 - Recent Questions, Troubleshooting & Support - Page 8

reed valves are in the intake rubber manifold, so the fuel mix can only go one way into the motor, Power valves are on the exhaust side of the motor and vary the exhaust porting to suit engine revs. They are not the same

I don't know you mechanical ability if you already tried setting the idle screw and it does not work i suggest you clean of have the carburetor cleaned problem usually is the low speed jet is clogged.
I suggest you have a mechanic take care of this problem.
there could be other problems bad crank seal or worn main bearing.

Hi. Go to this link and get the clymer book that will answer all of your questions and show you step by step how to do the overhaul

http://www.themotorbookstore.com/kawkx19.html

If you say it is definately sleeved it should be possible to bore it, you normally get one or two oversizes before it needs resleeving. If you are able to buy an over size piston from kawa or wiseco, chances are it can be bored.

.90 US quarts

incorrect jetting
incorrect ignition timing
incorrect plug heat range(could run a 9 or 10)
intake leaks
exhaust leaks
incorrect fuel oil mixture
overheating
is it burning the electrode off or carbon fouling the plug
sorry for the long list, there is probably a few you might discount as you have already checked

sounds like it's flooding...majority of pipes "don't" require jetting in older 250's...if they sent the jets with the pipe, find a happy medium in the numbers...for instance; if you had a 118 stock, and they said use 124, use a 120 instead...bottom line, you gotta reduce the fuel...quick trick ? just loosen the clamps on the carb and turn it sideways and remove the bowl...you don't have to remove the carb to re-jet...

you would need to change the main and the dust seal.
Pump out the piston then remove the dust and the main seals then clean out any white powder residue in the slots where the seals were, clean the piston with wet and dry paper or 1000 - 1200 grade glass paper and replace seals lubing up with brake fluid first do not use oil or grease as this will swell the seals and replace the piston, you may need to give this some GENTLE persuasion with a G glamp.
It's easier when bleeding your system to leave the caliper loose and also any ties that hold the brake line to the bike and try and get the caliper held above the fluid resevoir thus making it easier to expel the air as you have quite long brake lines in this bike.

Hope this helps

this is probably a specialist job, with some special tools and high pressure nitrogen for regassing

Two stroke motors with wet clutches are notorious for sticking when left for a period. Older oiler will leave a slight residue on ends of friction plates. If it is a regular thing after every stop, you will need to rinse clutch with a solvent. You don't need to dismantle if you are patient and carefull when applying solvent as it may discolour alloy cases and paintwork. Use a premium grade MOTORCYCLE GEAR OIL only and your problem will be solved if your clutch is A1 mechanically.

Look for where the tube from the radiator goes to the pump on side of the engine there should be 1 screw which has a fibre or copper washer,undo this.
Hold a suitable container covering the hole then take off the radiator pressure cap & watch it gush out!!
Flush with water ( put a hose to the pressure cap & rinse)
Replace bolt & fill rad & expansion tank with fresh coolant, run for 5 - 10 minutes then top up the expansion tank to max
expansion tank

Hope this helps (if so please mark as helpful !!)
Ride safe
Bike-Doc

is oil level up to par? make sure kill switch is set to run,(sometimes water or corrosion will make contact in the switct when it is in run) TEST ALL(ignition) fuses.replace any that do not work.

Yes, that is a plated cylinder so if it galls, or wears out, it cannot be bored out you have to put a new sleeve in it. The new sleeve will be able to be bored out so it will last for a long time. The resleeving is best left to a cycle shop or machine shop with the propper equipment, as it is an interfearence fit and the cylinder must be bored perfectly, then heated in an oven to be able to install the new sleeve.

Best would be to re-ring the piston you have unless it is damaged. To check the cylinder for wear, remove the ring from the piston and use a feeler gage keep using a smaller one till one fits, if less than .005 ok to re-ring. if more than that you might see if you can find a larger piston. one that fits at .0015 -- .0025 is good fit.

hhhmmm,
Being the front of the motor may make this suggestion a bit silly.... I have heard of this sort of problem before and it turned out to be air sucked through the throttle butterfly plate bushing. Happens only when certain vacuum is present and the throttle plate is in a particular position,revs at a certain point etc. Check for wear in the bushing. They can be re bushed, or get another carby for it. Check also that you dont have any intake manifold leaks. Use carby cleaner about the manifold,quick spray and the revs change means that you have an air leak, could cause a whistle/squeak noise also. Hard to find these sots of things. I could suggest having a fiddle with the throttle shaft when the noise occurs, to see if you can isolate it better.
Seeing that it comes from the front of the motor, check all your exhaust for good seal also. With a bit of back pressure, it may be a leaky exhaust up front. Bit of a worry that it keeps chopping up bearings. What oil mix are you using? I doubt that it is engine internals. Unless something is very wrong. May also be a water pump if my other suggestions wrong. If it relates just to revs, then sounds like a bearing... maybe waterpump. If it stops when you roll the throttle off keeping the same revs, i reckon intake or exhaust leak. Let me know what you find. Cheers
regards robotek

if it is piston slap,you will need pull the top off again and measure with a feeler gauge between the piston skirt and the sleeve, should only be a couple of thou

The exhuast valve set-up on a performance 2-stroke operates only at higher RPM.

650-700ml

hi,most two strokes in the mx range run about 40-1,but me being me i always prefer to run my 2 strokes a little bit oily around 33 or 35 -1,2 stroke oil is very cheap compared to scored barrels or seized big ends...cheers

hi,i assume you are referring to the centre nut in the centre of the clutch basket,as far as i know there is no shortcut,you will either have to make a holding tool to hold the clutch centre,if you have an old steel friction plate you can weld a handle to it and that will be sufficent to let you undo the nut,if you dont have any spares your only option will be to go to the agent and see if you can borrow the tool for doing it.alot of people(myself included) have tried to use a screw driver to lock the centre hub to the clutch basket,but i would not recommend trying it as it is very easy to damage the alloy splines that the clutch plates run in,you will then end up with a binding clutch if you damage them...hope this helps...cheers