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Urgent help - Xmas present for child

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Hi All, first poster here so if i stuff up on protocol, please forgive and educate. A mate of mine has dropped off a KTM EXC 200 1999 model which he picked up for his son's xmas present and was told all it needed was a set of piston & rings. Ive rebuilt a few 4 strokes for mates but never a 2-stroke, so if my questions are dumb, please forive and educate. I removed the head and bore and then drained the oil. From the manual there were two oil drain dpots, one on each side of the motor. One had a magnetic end and the other didnt. After draining the oil a slowly turned the crank to inspect it and noticed a heap of water sloshing around in the bottom around the crank. Pretty sure its not supposed to be there. Funny thing is it didnt drain out with the oil. Can someone explain? There is no seperate engine oil in a 2 stroke is there? Its just transmission oil? Is it the transmission oil that lubricates the crank as well? I'm guessing that it must have had a broken gasket to let water in to the bottom end and the extent of the damage is unknow. It was more the fact that there was water sloshing up around the crank when turned and the oil question that i really need an answer to asap. Help an aussie 4 stroke boy out?? Im just trying to help a kid get a good xmas present..

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somethings wrong. And the crank is separate from the trans, so the water wont come out when you drain the trans oil

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Could be that you bought a drowned bike (Water came in the airbox when the bike went for a swim), or someone left the plug out and it rained in there or someone stuck a hose up the exhaust for fun. Or, the headgasket leaked all the water/coolant into the crank area.

 

You must have drained the radiators from the drain bolt before you removed the cylinder. Did any water come out?

 

There's every chance there is rust-damage to the crank. You can take a chance, clean and lube the crank and rebuild the top half of the motor, only to find that the crank is shot. If there is rust on the crank bearings (difficult to see), and the crank spins freely, it's not going to last long before the motor starts to unravel and needs to be rebuilt again.

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Thanks HondaH8r904 & Swappa,

I think i understand now that the only lubrication for the crank etc if the oil in the fuel. Is That correct? There was water left in the radiators which makes me think it only leaked under pressure. I actually have the bike upside down in the shed trying to make sure all the water is drained. TRhe bike isnt worth the cost of doing a full bottom end rebuild as its probably only a $1500 bike at best and the costs of fixing the current motor will be more than that, Im just going to put a couple of flush's through the gear box put in the new piston and rings and put it back together. hopefully it doesnt disintegrate too quickly

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Hi, do you actually know what you are doing. A top end on a two stroke is very straight forward. You don't need to drain the gearbox oil. First thing you do is drain the rads and cylinder by removing the 10mm drain bolt in the water pump housing. You pull the bike over to the right (with the rad cap off) and get the last of the water out. Cylinder head off (if you are setting dimension X which you should do) cylinder off , replace base gaskets in accordance with X once you have new piston installed. Once you are happy with your deck height (Dimension X)rebuild. The only place water can get in the cases (unless as above it had been drowned) is the base gaskets or water pump o ring. Methinks you have slipped the cylinder up while there was still water in the rads, but if I'm wrong I apologise. Once you have it rebuilt, mind and bleed the head to get rid of any air. Bob.

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Thanks Heaps Bob or 7Tktm, no offense taken mate. I said at the start that i know nothing about 2 strokes. I did drain the radiators prior to removing cylinder, but i didnt drain it via the bolt you mentioned, hence there may still have bee quite a bit of water in the system somewhere. I've got it upside down inmy shed draining all of the water. My main issue was how the crank etc was lubricated. I wasnt 100% sure it was only via the oil in the fuel and not in part due to the transmission oil. It appears that the crank is only lubricated by the 2 stroke oil. I dropped the transmission oil as there were some small pinging marks on the top of the piston and the bottom of the head where a small piece of metal must have come through. No damage to the bore at all which was lucky. Is there any other way in your opinion to get the water out from around the crank? maybe some other bolt that cleans out that area. I really dont want to put it all back together until im 1--% positive that there is no water left in the system. I'll definitely bleed the water system as instructed. And measurement x has been done.and adjustments made. Any help will be appreciated!!

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Thanks Heaps Bob or 7Tktm, no offense taken mate. I said at the start that i know nothing about 2 strokes. I did drain the radiators prior to removing cylinder, but i didnt drain it via the bolt you mentioned, hence there may still have bee quite a bit of water in the system somewhere. I've got it upside down inmy shed draining all of the water. My main issue was how the crank etc was lubricated. I wasnt 100% sure it was only via the oil in the fuel and not in part due to the transmission oil. It appears that the crank is only lubricated by the 2 stroke oil. I dropped the transmission oil as there were some small pinging marks on the top of the piston and the bottom of the head where a small piece of metal must have come through. No damage to the bore at all which was lucky. Is there any other way in your opinion to get the water out from around the crank? maybe some other bolt that cleans out that area. I really dont want to put it all back together until im 1--% positive that there is no water left in the system. I'll definitely bleed the water system as instructed. And measurement x has been done.and adjustments made. Any help will be appreciated!!

look like any of these???

https://www.google.com/search?q=detonation+marks+on+piston&biw=1600&bih=763&tbm=isch&imgil=Yjgah7zG1wcSfM%253A%253BGuRQm5UObNuyqM%253Bhttp%25253A%25252F%25252Fwww.volvo300mania.com%25252&%$#@!%25252Fforum%25252Fviewtopic.php%25253Ff%2525253D6%25252526t%2525253D2295%25252526start%2525253D0&source=iu&pf=m&fir=Yjgah7zG1wcSfM%253A%252CGuRQm5UObNuyqM%252C_&usg=__e2apc2c9UrDx863csW-IJhxclVg%3D&ved=0ahUKEwjM35yo66zJAhWKbT4KHeU2BXkQyjcIJQ&ei=EVNWVoyTJIrb-QHl7ZTIBw#imgrc=Yjgah7zG1wcSfM%3A&usg=__e2apc2c9UrDx863csW-IJhxclVg%3D

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What is xmas???

 

(just a quick explanation) Xmas is actually a way to remove "Christ" from Christmas, but to simply say "Mas" makes no sense, therefore the anti religion or Atheists use "Xmas" to say "Christmas".  Some people may not understand that this is why "Xmas" is used, so unless you fall into one of those groups I would continue to use "Christmas".

 

As for finding coolant in the crank (not transmission) area of a 2t when it was disassembled, I would have to believe that it got in there when it was disassembled as there is no way for coolant to survive in the crankcase of a running 2t. 

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Thanks sig06, it's quite possible there was water still in the cylinder and heads water jackets. Once I've drained the water, should I put some sort of oil or lubricant in the cavity surrounding the crank / Conrod etc? Thanks for help

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(just a quick explanation) Xmas is actually a way to remove "Christ" from Christmas, but to simply say "Mas" makes no sense, therefore the anti religion or Atheists use "Xmas" to say "Christmas".  Some people may not understand that this is why "Xmas" is used, so unless you fall into one of those groups I would continue to use "Christmas".

 

As for finding coolant in the crank (not transmission) area of a 2t when it was disassembled, I would have to believe that it got in there when it was disassembled as there is no way for coolant to survive in the crankcase of a running 2t.

Think you sir ..... CHRIST x ....got it.

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Hi again, take it you drained the water through a rad hose so the water in the cylinder and head has dropped into the cases. Not a great issue since you've had the motor upside down and got rid of most of it. There's not much room down there. Of concern are the marks on the piston and head. You can't have these. There are only 2 possibilities. Is the piston intact around the edge of the crown, ie no part melted off which bounced around before going out the pipe. Is the top of the piston pock marked around the edge or the whole crown. If it hasn't come from the top then it has to come from the bottom, usually part of the cage of a main.

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If you are that unfamiliar with 2-stroke engines first you need to read and re-read the bike's service manual and research general 2T infos

or else you're just going to get yourself into deeper trouble (mechanicaly and financialy) by just 'guessing' how to troubleshoot, repair and tune them.

 

'pock marked' or surface erosion around the edge of the piston's crown could be a sign of detonation.

If severe enough, the rod/crank bearings could also have been pounded so will have to be verified.

 

If not detonation, perhaps mechanical damage from something loose flying around (piece of ring, bearing needle/cage etc.)

As a 2-stroke combustion chamber and bottom end communicate thru the cylinder's transfer ports,

anything 'loose' rattling around on top of the piston has a chance to also create havoc in the crankcase as well.

 

Keep in mind that simply slapping on a new piston/ring on top of a bottom end of unknown condition (16 year old engine) would be a gamble.

Edited by mlatour

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I agree with mlatour and he sums it up nicely. Without seeing your piston it is hard to say, but your description doesn't sound like det, more like a piece of debris. If the piston crown above the top ring is all there and there is no part of the ring(s) missing or part of the top of the exhaust port (weak point) then it has come from below which is an issue. Bet you're wishing you'd said, 'heh, I know faff all about 2 strokes, get another mate to look at it'. Bob.

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Thanks sig06, it's quite possible there was water still in the cylinder and heads water jackets. Once I've drained the water, should I put some sort of oil or lubricant in the cavity surrounding the crank / Conrod etc? Thanks for help

 

No, you really don't have to put anything in the crank area, blowing it out with compressed air and keeping it clean is normally good enough when your just replacing the top end.  Even in this case where "some" coolant may have dribbled onto the crank, just blowing it out with compressed air should do it.  After that anything left will get burned up within the first few minutes in the first ride.

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(just a quick explanation) Xmas is actually a way to remove "Christ" from Christmas, but to simply say "Mas" makes no sense, therefore the anti religion or Atheists use "Xmas" to say "Christmas".  Some people may not understand that this is why "Xmas" is used, so unless you fall into one of those groups I would continue to use "Christmas".

 

As for finding coolant in the crank (not transmission) area of a 2t when it was disassembled, I would have to believe that it got in there when it was disassembled as there is no way for coolant to survive in the crankcase of a running 2t. 

 I don't think "Xmas" is an atheist thing at all. X is a cross. The cross is the symbol of Christianity. Also I think the Greek translation of Christ is spelled with an X. (I believe one of the more popular versions of the Bible was written in Greek.)

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 I don't think "Xmas" is an atheist thing at all. X is a cross. The cross is the symbol of Christianity. Also I think the Greek translation of Christ is spelled with an X. (I believe one of the more popular versions of the Bible was written in Greek.)

 

Nothing personal, but I really really really do not want to turn this thread into a bible lesson, in the future if you wish to correct someone in a thread without staying on topic then ... don't post.  That said, it's true that the Greek shorthand letter for Christ is "X", however, this thread is in English not Greek and in English it's used to remove Christ from Christmas.  As evidence pick up any English bible and look for Xmas ~ you'll never find it.  If you want to pursue this topic please post something in the "General" forums.

 

Now let's talk dirt bikes!  Any news on the rebuild??

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What is xmas???

 

 

(just a quick explanation) Xmas is actually a way to remove "Christ" from Christmas, but to simply say "Mas" makes no sense, therefore the anti religion or Atheists use "Xmas" to say "Christmas".  Some people may not understand that this is why "Xmas" is used, so unless you fall into one of those groups I would continue to use "Christmas".

 

As for finding coolant in the crank (not transmission) area of a 2t when it was disassembled, I would have to believe that it got in there when it was disassembled as there is no way for coolant to survive in the crankcase of a running 2t. 

 

 

Nothing personal, but I really really really do not want to turn this thread into a bible lesson, in the future if you wish to correct someone in a thread without staying on topic then ... don't post.  That said, it's true that the Greek shorthand letter for Christ is "X", however, this thread is in English not Greek and in English it's used to remove Christ from Christmas.  As evidence pick up any English bible and look for Xmas ~ you'll never find it.  If you want to pursue this topic please post something in the "General" forums.

 

Now let's talk dirt bikes!  Any news on the rebuild??

 

fox news strikes again...

 

 

its just an abbreviation...

as evidence check the dictionary as far back as 1800...

https://en.wikipedia.org/wiki/Xmas

http://www.snopes.com/holidays/christmas/xmasabbr.asp

http://www.merriam-webster.com/dictionary/xmas

 

good luck with your project!!!

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