Do i need a cylinder re plate ?

Tryhard
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Tryhard
Edited Date/Time 3/7/2018 5:56pm

In your opinion do i need a cylinder replate? i see some marks and stuff , opinions are welcome thanks!







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kb228
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kb228 3/7/2018 12:05pm
3/7/2018 12:05pm
Yea... spot between your exhaust ports looks f’ed
Tryhard
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Tryhard 3/7/2018 12:10pm
3/7/2018 12:10pm
yeah ill try and get a better pic but im sure it needs it , man im into this bike for a pile already!
Tryhard
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Tryhard 3/7/2018 12:19pm
3/7/2018 12:19pm Edited Date/Time 3/7/2018 12:25pm
Okay that maybe a little better picture

I checked everything with calipers and everything is in spec according to service manual . I just dont have to much experience with this . I have looke dta some other comparisons online when people were told they need a replate . and this one seems as if it has just been plated not to long ago im not sure thats why im asking.








Matt Fisher
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Matt Fisher 3/7/2018 1:04pm
3/7/2018 1:04pm
I'd say run it. The marks you see on the exhaust bridge are to relieve it, creating a larger gap so it doesn't become a hot spot and cause a seizure. Same reason many forged pistons will have small holes drilled in them where they would mirror the exhaust bridge.

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Tryhard
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Tryhard 3/7/2018 1:50pm
3/7/2018 1:50pm
Matt Fisher wrote:
I'd say run it. The marks you see on the exhaust bridge are to relieve it, creating a larger gap so it doesn't become a hot...
I'd say run it. The marks you see on the exhaust bridge are to relieve it, creating a larger gap so it doesn't become a hot spot and cause a seizure. Same reason many forged pistons will have small holes drilled in them where they would mirror the exhaust bridge.
okay thanks alot mate
Bruneval
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Bruneval 3/7/2018 3:43pm
3/7/2018 3:43pm
You didn’t say which bike it is, but it looks like a 2002+ CR250, in which case, the exhaust bridge definitely needs to be relieved so that is correct.

If that was mine, I would deglaze the cylinder with some scotchbrite and WD40 and run it.
Tryhard
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Tryhard 3/7/2018 4:47pm
3/7/2018 4:47pm
Bruneval wrote:
You didn’t say which bike it is, but it looks like a 2002+ CR250, in which case, the exhaust bridge definitely needs to be relieved so...
You didn’t say which bike it is, but it looks like a 2002+ CR250, in which case, the exhaust bridge definitely needs to be relieved so that is correct.

If that was mine, I would deglaze the cylinder with some scotchbrite and WD40 and run it.
Sorry your right i did not mention that , this is a 2000 kx125 .
Paw Paw 271
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Paw Paw 271 3/7/2018 5:08pm
3/7/2018 5:08pm Edited Date/Time 3/7/2018 5:08pm
For what it's worth....
I see a cylinder where the proper work has been done in the past, but one that has also been abused by running the piston and rings beyond the normal service life with either a dirty air filter or an air filter that is letting some dirt get through and thus the cylinder markings.

I would suggest that you clean the cylinder up with WD40 and scotch brite pad to see what it looks like then.
Then install a new piston with the exhaust bridge oil holes drilled correctly and the ring end gap set correctly. Do a compression test. and then run it until you see the compression start dropping off and then do another top end.

I would also take a good look at the air cleaner system.

Paw Paw
Tryhard
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Tryhard 3/7/2018 5:56pm
3/7/2018 5:56pm
Paw Paw 271 wrote:
For what it's worth.... I see a cylinder where the proper work has been done in the past, but one that has also been abused by...
For what it's worth....
I see a cylinder where the proper work has been done in the past, but one that has also been abused by running the piston and rings beyond the normal service life with either a dirty air filter or an air filter that is letting some dirt get through and thus the cylinder markings.

I would suggest that you clean the cylinder up with WD40 and scotch brite pad to see what it looks like then.
Then install a new piston with the exhaust bridge oil holes drilled correctly and the ring end gap set correctly. Do a compression test. and then run it until you see the compression start dropping off and then do another top end.

I would also take a good look at the air cleaner system.

Paw Paw
Thanks alot for the detailed response Paw Paw , your knowledge always seems like a savior here in these forums ....Yes this bike has been road hard and put away wet , i am currently going through the suspension and its a nightmare , the engine was worse . i have it all apart right now , and had to purchase a new case set . I do believe at one time the proper care had been taken upon this Motorcycle but not by the previous owner . Thanks alot for your response , and opinion !

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