2004 cr250 help

keeptwostrokesalive
Edited Date/Time 4/2/2012 4:23am
I just bought a 2004 cr250 with 7 total hours on the bike for $1700. I noticed the bike makes a knocking noise that seems to be coming from the engine. I took it to a friend who knows a lot about dirt bikes and he told me that he believes it is just the power valves rattling around and it should be fine. What i want to know is if that sound is just a common thing for the 2004 cr250? Is there anyone on here that ownes one and it does the same thing?
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TerryK
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TerryK 3/31/2012 12:10pm
3/31/2012 12:10pm
keeptwostrokesalive wrote:
I just bought a 2004 cr250 with 7 total hours on the bike for $1700. I noticed the bike makes a knocking noise that seems to...
I just bought a 2004 cr250 with 7 total hours on the bike for $1700. I noticed the bike makes a knocking noise that seems to be coming from the engine. I took it to a friend who knows a lot about dirt bikes and he told me that he believes it is just the power valves rattling around and it should be fine. What i want to know is if that sound is just a common thing for the 2004 cr250? Is there anyone on here that ownes one and it does the same thing?
Piston slap? How do you know it's only got 7 hours on it?
keeptwostrokesalive 3/31/2012 12:51pm
3/31/2012 12:51pm
The guy told me it only has 7 hours on the bike. I can tell its been sitting for a awhile and hasnt been used much. The guy i took it too thought that it sounded fine and shouldnt be a problem. How can i find out if it is the piston slapping around?
moto814
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moto814 3/31/2012 2:30pm
3/31/2012 2:30pm
Open the engine up and look/measure/test.

Logic, it escapes most people.

-Steve
keeptwostrokesalive 3/31/2012 3:21pm
3/31/2012 3:21pm
moto814 wrote:
Open the engine up and look/measure/test.

Logic, it escapes most people.

-Steve
A simple answer with no douche remarks would have been nice.

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insane one
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insane one 3/31/2012 5:04pm
3/31/2012 5:04pm
Remove the powervalve cover. Then check the cables for slack. Do a compression test. It would be a good idea to refresh the top end anyway.
keeptwostrokesalive 3/31/2012 5:08pm
3/31/2012 5:08pm
At this moment i am taking the cylinder head off so i can inspect the top end and the cylinder. I am most likely going to do a top end rebuild.
insane one
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insane one 3/31/2012 5:11pm
3/31/2012 5:11pm
Ok but did you notice if the powervalve cables were stretched or broken?
keeptwostrokesalive 3/31/2012 5:55pm
3/31/2012 5:55pm
insane one wrote:
Ok but did you notice if the powervalve cables were stretched or broken?
I havent gotten the power valve cover off yet. If it was stretched or broken like you say would that cause the knocking sound in the engine?
insane one
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insane one 3/31/2012 6:00pm
3/31/2012 6:00pm
I am not 100% sure on that. But that is what I would look at first..
insane one
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insane one 3/31/2012 6:04pm
3/31/2012 6:04pm
While you have it torn down chech the rod for slop. It could also be a bad rod bearing.
keeptwostrokesalive 3/31/2012 6:33pm
3/31/2012 6:33pm
Once i get her full apart i am definitely going to do a full engine check. Hopefully i will only have to do a top end rebuild. I thikn that should get rid of the piston slap.
Craze
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Craze 4/1/2012 2:33am
4/1/2012 2:33am
My buddy had one with the same symptoms as your describing (03)...He had to replace the Cylinder
keeptwostrokesalive 4/1/2012 6:24am
4/1/2012 6:24am
Well to my dissaopointment when i took the cylinder off the piston was cracked and had two holes in it. The cylinder has some slight grooves in it so im probably going to have to get it bored out.Sad
moto814
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moto814 4/1/2012 8:00am
4/1/2012 8:00am
moto814 wrote:
Open the engine up and look/measure/test.

Logic, it escapes most people.

-Steve
keeptwostrokesalive wrote:
A simple answer with no douche remarks would have been nice.
That was a simple answer with no "douche" remarks. And strangely it was proven by your last post about:

Well to my dissaopointment when i took the cylinder off the piston was cracked and had two holes in it. The cylinder has some slight grooves in it so im probably going to have to get it bored out.


Unless the cylinder is already sleeved, don't bore it. Send it to one of the plating shops out there and have it replated. Personally I would go with PowerSeal ( [url]http://www.powersealusa.com[/url] ) as they are the best I've seen in the US.

Seriously, if you think what I said was harsh, you should find a different moto board. This place has had it's heart and soul ripped out recently, but there are a few of us still here that remember the glory days. Hopefully those days will be back soon.

Oh, spelling and punctuation also count.

-Steve
keeptwostrokesalive 4/1/2012 9:52am
4/1/2012 9:52am Edited Date/Time 4/1/2012 9:53am
Here is the two holes in the piston.


Here is the crack.


Its hard to see in this picture but the fin looks cracked on the cylinder but im not sure if thats how it comes standard or is it really cracked.


Heres another.
keeptwostrokesalive 4/1/2012 11:12am
4/1/2012 11:12am
Well when i took the airbox out i noticed there was a lot of dirt in there. So obviously the previous owner did not properly take care of the filter which ended in dirt getting in the engine causing the piston to give way.
RMRider1
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RMRider1 4/1/2012 5:31pm
4/1/2012 5:31pm
Dude, that thing looks aweful! Have it replated!
keeptwostrokesalive 4/1/2012 5:44pm
4/1/2012 5:44pm
RMRider1 wrote:
Dude, that thing looks aweful! Have it replated!
I am most likely going to get it replated. I was hoping this bike was going to be a cheap project but its turning out to be a little more than what i bargained for.
List of things i need to get for bike:
1. Tires
2. Cylinder replated, wiseco top end and gasket set
3. fork seals
4. New air filters
and a lot more little things here and there. Hopefully in the end this bike will turn out how i want it to so it wont be a waste of my time.

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haydos25
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haydos25 4/1/2012 8:11pm
4/1/2012 8:11pm
Ouch, its amazing how much damage can be done to a bike in 7 hours hey hahaha.

When you bought the bike did you not start it up or look at it first? Weeping fork seals, bald tires, disintegrated air filter wasnt enough of a sign that he may have been pulling your chain? Did he also manage to sheer a few teeth off the rear sprocket and trash a chain in those 7 hours aswell? Or did the guy just tell you it had 7 hours on it and you took his word for it and are now dealing with the shitfight that is dodgy used bikes?

Hope you can get it all sorted, live and learn i guess hey.
keeptwostrokesalive 4/2/2012 4:23am
4/2/2012 4:23am
haydos25 wrote:
Ouch, its amazing how much damage can be done to a bike in 7 hours hey hahaha. When you bought the bike did you not start...
Ouch, its amazing how much damage can be done to a bike in 7 hours hey hahaha.

When you bought the bike did you not start it up or look at it first? Weeping fork seals, bald tires, disintegrated air filter wasnt enough of a sign that he may have been pulling your chain? Did he also manage to sheer a few teeth off the rear sprocket and trash a chain in those 7 hours aswell? Or did the guy just tell you it had 7 hours on it and you took his word for it and are now dealing with the shitfight that is dodgy used bikes?

Hope you can get it all sorted, live and learn i guess hey.
When i bought the bike i knew it was going to need tires, and a fork seals. Somehow though i did not notice the sound coming from the engine though. Even though the bike isnt what i thought it really was im still i made the purchase because in the end when she is all finished its going to look and ride really well.

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