KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: GRARA on August 21, 2014, 11:35:52 PM
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Hi newbie here.....just looking for some help/advice on the problems im having with my recently purchased 99KX250evo.
1).There is a fuel leak which is dripping from the underside of my engine roughly where the oil drain plug is,its not coming from my carb,which we first thought was the floats sticking and fuel running out over the flow and round the engine,but its dry around the top of the engine/carb area and ive moved the over flow hose out the way?
2).Ive had KXs in the past and this one is seriously lacking something,it has plenty torque,no bogging etc,but just doesnt have the lethal kick of other KX250s......it is kind of like riding a 4stroke,no lethal power band.My sons 2001 YZ80 runs circles round it on acceleration and top end.
3).It smokes like a dragon and serious amounts of spooge leaks from the front of the engine where the exhaust joins,ive re-packed the exhaust which has stopped the majority of the smoke but if i gun it it still leaves half a mile of smoke behind me.
4).It wont idle,turning the idle screw does nothing.
Things ive checked.
Had the carb off and on too many times now cleaned,aired all jets etc.
New air filter.
Reeds are fine,checked gaps are all in spec.
New Rings/piston,barrel is spot on.
Re-packed the exhaust.
Any advice would be GREATLY appreciated.
Cheeers Graeme
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Possibly time to split cases unless your jetting is so far off or the air filter is way over oiled, but not having a noticeable bog makes me think otherwise (are you using race gas or a higher octane fuel where the previous owner had it jetted for a heavier or cheaper fuel , the jetting could be quite a bit off but that doesn't entirely explain the seepage on the bottom of the cases unless there's so much unburnt fuel pooling down there it's seeping through the sealent, which the cases would have to be split to resolve along with correct jetting). Sounds like you could have a multitude of issues, strange fuel seepage could be coming from the center cases if sealent between the matched cases is deteriorated. Clutch side crank seal could be to blame for the excessive smoke, especially at higher rpm's. Have you noticed a loss in tranny oil or a little less when changing?
I'd start with pulling the ignition cover off and move the flywheel up & down to check for big bearing play (a bearing going will stress the piston & rings, you'll have to replace them and it'll cause the crank seals to leak air and/or tranny juice). If you've had this bike a while & haven't replaced the reeds, I would do so. Who knows the last time they were replaced, I replace mine every top-end (for a reason, they affect performance when they're slacked). Measure the amount of oil going in & measure what comes out at an oil change after, keep an eye on the site glass to make sure if it is consuming it that you don't run it too low, but if you're getting less out by a noticeable margin, your crank seal on the clutch side is bad, gotta split cases. When was the last time the powervalves inspected and/or cleaned? It's fairly hard to diagnose a running issue over the computer, but those are the starting points from what you're saying that I'd start with.
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Hi newbie here.....just looking for some help/advice on the problems im having with my recently purchased 99KX250evo.
1).There is a fuel leak which is dripping from the underside of my engine roughly where the oil drain plug is,its not coming from my carb,which we first thought was the floats sticking and fuel running out over the flow and round the engine,but its dry around the top of the engine/carb area and ive moved the over flow hose out the way?
2).Ive had KXs in the past and this one is seriously lacking something,it has plenty torque,no bogging etc,but just doesnt have the lethal kick of other KX250s......it is kind of like riding a 4stroke,no lethal power band.My sons 2001 YZ80 runs circles round it on acceleration and top end.
3).It smokes like a dragon and serious amounts of spooge leaks from the front of the engine where the exhaust joins,ive re-packed the exhaust which has stopped the majority of the smoke but if i gun it it still leaves half a mile of smoke behind me.
4).It wont idle,turning the idle screw does nothing.
Things ive checked.
Had the carb off and on too many times now cleaned,aired all jets etc.
New air filter.
Reeds are fine,checked gaps are all in spec.
New Rings/piston,barrel is spot on.
Re-packed the exhaust.
Any advice would be GREATLY appreciated.
Cheeers Graeme
have you done a compression test?...you say "new rings/piston, barrel is spot on"...but that doesn't mean anything without doing a compression test.
leak down test should be at the top of the check list as well...that'll tell you if you have a bad seal/leak.
what is the current jetting you have?
have you checked if the KIPS valves are opening?...this won't cause it to smoke excessively, but it certainly won't have any sac if they're not working/opening.
it's possible the bottom end got flooded with fuel and never got flushed out too....that "could" explain the excessive smoke and spooge coming from the cylinder/pipe connection, and the strange leak near the drain plug :-o
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Thanks for the info much appreciated.... Not sure about jetting never had to play around with that side of things, only ever had to do top end stuff ( the easystuff)..
Splitting the engine fills me with fear!
Does this sound like it needs to be handed into a shop and let the people who no what they are doing perform surgery?
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Thinking about past issues we've expierenced, it could be an stator going bad (not enough spark to burn everything off), excessive ring blow-by (beat cylinder) , but I really think it's either jetting or a crank seal related issue but no way to tell over the internet. Pull the carb apart and get the pilot, needle & clip position and main jet sizes along with the OEM recommendation, the fuel quality/octane, the brand of pre-mix oil & ratio and your altitude. Though you can't jet a bike over the internet, at least it'll give us someting to work with or an idea for your altitude, fuel quality & pre-mix oil/ratio against you current jetting versus what the OEM standard jet settings (and the OEM baseline of 94 octane/ 32:1/ sea-level).
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Thanks for the info much appreciated.... Not sure about jetting never had to play around with that side of things, only ever had to do top end stuff ( the easystuff)..
Splitting the engine fills me with fear!
Does this sound like it needs to be handed into a shop and let the people who no what they are doing perform surgery?
Go through everything you can, test electrical, jet properly, and compression and leak down test before sending the motor out! I learned the hard way spent 18 hundo on a rebuild and mods to get it back with the same issues. 60 bucks for a new coil and it was fixed!! BRIGHT SIDE: Got basically a brand new motor and piece of mind.
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Thanks again guys.....I noticed last night that the rubber gland on the stator cover was hanging out!!!!
God only knows what rubbish has gotten inside,i will remove the cover today and give it the once over,hopefully find loads of rust in the inside,and its just a good rub down it needs.
I will let u no the outcome anyway.
And again thanks.
Graeme
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Removed fly wheel last night and it looks like a new stator has been fitted not long ago..no rust/corrosion :-(
fuel leak seems to be getting worse,its quite clear now where its coming from,its about 3 inches below the exhaust where the casings join,its now contantly running out with a greyish tint to it..
Going to remove the engine/top end and perform mild surgey and see whats going on.
Its also revving quite high now on start up so must be drawing air now aswell.Also removed the left power valve cover and its full of black sticky spooge(prob.why it aint working properly). i will remove the front casing once my engine is out and check the valves at the front,im guessing they will be even worse.
Might have to consider cost now,am i going to be cheaper just finding another engine or forking out who knows how much on engine re-build.
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Cost is a factor for most of us.
My experience with used engines has rarely been a happy one.
Even if it takes a bit longer and cost's a bit more, I'll build it myself.
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I 2nd the rebuild rather then sourcing another engine unless it is absolutely clean & very low hours (a needle in a hay stack find), otherwise you'll probaly have to do all the same stuff this one needs.
Make sure the entire bike & engine especially, is scrubbed with a toothbrush clean! If not, you risk ruining a lot of expensive engine bearings upon disassembly if any dirt gets in there that you can't get wash out! Time for a powervalve disassembly, clean & inspect; new main bearings, crank seals (Cometic nitriles if running ethanol laced pump), new OEM crank assembly (or have the existing rebuilt by a reputable person), inspect the cylinder closely for minute fractures/ plating flaking/ worn or polished looking cross-hatching/ lip at top of cylinder were the rings stop; new piston/rings/pin/bearing and while you got it all apart, replace all the external engine case seals (no better time then when there's no shafts in the way). Expensive, yes! Worth it? Oh yeah! Do a job right once with quality parts once and only pay for it once!
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yup...like I've always said...whenever buying a used bike, you have to go into it expecting to drop $1K right off the top!....between the two builds I have in my 500 over the last 4 years, I've spent either side $18K...and when I did my 250, that was another $3500, both bikes were rebuilt with ALL OEM parts ...it all depends on how reliable you want your bike to be. You can either cheese out on the rebuild, and only replace "some" things, and always be worried if your bike is gonna make it through the day and get you home when you're 40 miles away...or, replace everything but the engine cases like I did, and have a COMPLETELY brand new motor.
The more things you keep uniformly new, the better.
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Cheers guys,i agree now getting a new engine is NOT the way forward as i could be taking on the same problems.
Im a mechanical engineer to trade so im going to get myself a Haynes manual and learn how to do the job myself,better to learn and get clued up on my own bike,if i dont learn how to fix it now i never will. :-D
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If you haven't gotten one yet, purchase the factory Service Manual. I like having one for every bike owned, don't always need it but it's invaulable when you do.
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I have down loaded the " Motorcylcle Service Manual " but its not that clear on how to do stuff..
Is the " Factory Service Manual " different? i.e does it show you how to split the engine etc?
Should have joined this site years ago lol
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i.e does it show you how to split the engine etc?
yes, but you'll need a case splitter if you don't already have one...
http://www.motionpro.com/motorcycle/partno/08-0245/
you can find them cheaper if you look around.
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Ah thanks ...kind of pricey,i will check on internet for anything in the U.K, also what am i better off replacing while the engine is split?
Full new gaskets,oil seals,pos.new piston kit....
is there anything else that needs replaced?
Thanks again.
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you probably don't want to hear it...but at the very least, you want to replace every bearing, every seal, every snap ring...thoroughly inspect every gear/fork/shaft/shift drum in the tranny for wear, and replace anything that looks questionable.
thoroughly inspect the clutch hub, basket, pressure plate, fiber and metal plates.
get a complete Cometic gasket set...
http://www.cometic.com/
go with a Wossner piston...
http://www.wossnerpistons.com/products/mode/filter/search/Kawasaki?fitment-category-id=BBB40D59-0BEE-E011-963B-000C29296656&fitment-category-name=2+Off-road
I replaced the entire tranny/bottom end in my 500 last year, because I plan on keeping it for a long time...if you plan on keeping yours for awhile, I'd replace as much as you can as well.
yeah that particular puller is pricey, but it's good, just shop around, e-bay has them too...you could always rent a puller/case splitter if you don't want to buy one also.
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WOW ........need to do some serious overtime!!
Ive already ordered a new piston kit,full gasket kit,oil seal kit and a full bearing kit from ebay...probably not the best kit in the world but im sure (hopefully) it will do my injured ride some good.
Ive managed to get some help from a friend of a friend,who is a bike mechanic and he is going to show me how to do all this step by step,and if it needs other new parts on the way he will advise.
Thanks again for the much needed advice.
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well at least you're replacing the bearings and seals, hopefully they're good quality...but definitely get new snap rings for the tranny....there's nothing worse than doing a rebuild, and then having a snap ring break just hours after the "break-in" period...then you have to tear it all back down and start over again.
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Snap rings?? this probably sounds stupid.... but how many do i need?
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part numbers.....
snap ring 25mm...92033-1089...there are 4 of these
snap ring 18mm...92033-029...only one of these
snap ring 24mm...92033-026...only one of these....this is the front sprocket snap ring.
about $30 to your door should cover it through Rocky Mountain....or who ever you decide to use.
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Thanks Foxx4Beaver you really know your stuff :-D :-D :-D :-D :-D :-D
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Thanks Foxx4Beaver you really know your stuff :-D :-D :-D :-D :-D :-D
being old helps :-P
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Ok here goes...after tear down all parts seem to be quite new...but replacing seals and bearings anyway,looks like the piston rings were shot (just shows you that when the rings LOOK ok they prob.arent)causing fuel to seep down into the crank and eating through the casing sealant.The casing has a soft spot where the previous owner had used a screw driver to separate the casings and damaged the edges,then filled the damaged area with sealant,and the fuel which was going past my rings found a way out!!!
So,getting my damaged area re-welded and sanded down before we seal engine together again.
The inlet rubber from carb to engine was also burst causing engine to take in air..!!
Annnnnd another problem...the teeth on the drum valve (power valve)have sheered ,this is why my power valve has never worked...
Does anyone know if Kawaski Part no 12005-1182 will fit onto 98/99 KX250 they look identical.....Foxx4Beaver needing your help here????
Lesson learned here people.....I checked rings --they LOOKED fine,i checked the carb so many times,but over looked the inlet rubber,even after i had removed the reeds at least 5 times!!!!
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what year bike is the 12005-1182 supposed to be for?
I have the 99's listed as...
Left...12005-1284
Right...12005-1285
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12005-1182 VALVE-EXHAUST is the left 93 94 says only fits 93 94
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I found this on ebay....Kawaski Part no 12005-1182 is 93/94 but looks exactly the same ......
To buy a dirty second hand power valve assembly in Scotland its going to cost me £100 ,but all i need is the one drum valve,im not cutting corners here and im not paying for something i dont need.Im sure u would agree.
Thanks for the RAPID response guys!!
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well I just incounted the same problem with my 87 250. i sheared one of the gears on one valve but had to buy a complete set second hand so now I got some spare bits lol
If the valves were the same I would think that Kawie would keep same part number but only one way to no for sure someone here may no more I just searched for the answer for you :wink:
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Well bens87braap i might just do the same,that way i will also have some spares :-D
Were your valves all carboned up also?
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my left valve was destroyed on inspection my bike was allways like that now im not running any power valves lol
This is what I pulled out of the motor
(http://i1289.photobucket.com/albums/b501/ben_brown5/2014-06-28162315_zpsd0e95a2b.jpg)
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I found this on ebay....Kawaski Part no 12005-1182 is 93/94 but looks exactly the same ......
To buy a dirty second hand power valve assembly in Scotland its going to cost me £100 ,but all i need is the one drum valve,im not cutting corners here and im not paying for something i dont need.Im sure u would agree.
Thanks for the RAPID response guys!!
12005-1182 will not fit into the 1999 cylinder. Although they "Look" the same the diameter & relief cutouts are different.
Hope this helps,
DoldGuy
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Thanks for the info DoldGuy,i was almost ready to order the part..glad i never.
Thanks again.
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ok feeeeewww........can anyone tell me if there is a difference between the 98 and 99 power valve?
Ive been offered the kit from a 98 but not sure if they will fit my 99???
Sorry for being a pain in the ass..
But it will be worth it to get another green machine back from the brink of death!!
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ok feeeeewww........can anyone tell me if there is a difference between the 98 and 99 power valve?
Ive been offered the kit from a 98 but not sure if they will fit my 99???
Sorry for being a pain in the ass..
But it will be worth it to get another green machine back from the brink of death!!
They are the same....
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Thanks again DoldGuy.
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Well its been a while buuuut finally got my bike back yesterday.....New power valve kit,new seals,new piston,new reeds,new clutch etc. Rode the bike for 2 hours last night with a permanent smile on my face and even let slip a couple of loud laughs..
Love this new machine..and thanks all for the input to its problems :-D :-D :-D
Also had a quote to get a new governor rod made for the power valve........£500-£700 !!!!!!!!!
I love ebay £70 for a second hand kit :wink: