Pics of cylinder
- 87CR500Rider
- Posts: 168
- Joined: January 4th, 2008, 7:47 am
- Location: San Antonio, TX
Pics of cylinder
Some pics of the cylinder and piston off my 87'. I bought the bike, rode it, and am rebuilding it now and here's what I found. I'm assuming it's been resleeved. Check out how the sleeve looks where it meets the cylinder. I've never had a resleeved cylinder so I can't tell you what a good one looks like. I can tell you there isn't a port on it that's smooth. The clutch basket dang near looks brand new too. Not a groove on it.
Here's the piston.
The head.
Here's the piston.
The head.
- dannygraves
- Posts: 8020
- Joined: June 1st, 2007, 2:03 pm
- Location: Las Vegas, NV
If you cleaned the jug and head first if would be a good deal easier to see what's been going on
I think your sleeve fitment looks normal. It looks to me that it's been bored once already and the exhaust bridge wasn't relieved and they didn't chamfer the port edges or not well enough. I think you smeard the exhuast side of the rings and the intake side of the piston looks cracked as well inside the skirt. I beleive that clean spot on the intake side of the head represents a hot spot. It was mentioned on NASCAR TV that teams try and get the heads to look as uniformly as possible. And that spots as seen on your head was indication of a no no. But I don't know man I'm just a dirt bike nerd! But I've never seen a spot like that on a head before...
I think your sleeve fitment looks normal. It looks to me that it's been bored once already and the exhaust bridge wasn't relieved and they didn't chamfer the port edges or not well enough. I think you smeard the exhuast side of the rings and the intake side of the piston looks cracked as well inside the skirt. I beleive that clean spot on the intake side of the head represents a hot spot. It was mentioned on NASCAR TV that teams try and get the heads to look as uniformly as possible. And that spots as seen on your head was indication of a no no. But I don't know man I'm just a dirt bike nerd! But I've never seen a spot like that on a head before...
'03 CR500 powered by...umm...a new motor?
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ive seen quit a few cracked cast pistons, yours is one of the worst ive seen. the crack appears to go up to the top of the wrist pin, i think it would of exploded before too much longer. these pics arent the best but it appears it may be a resleeve, it also appears they didnt bothered to match it up very well at the bottom transfer area though. do you know the history on the crank, rod, tranny bearings/seals ? now is a good time to have a look at everything if your unsure of their condition
- britincali
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ive seen a few cylinders and never known honda to send one out looking like this. you can see where the sleeve doesnt match real well into the transfer. his other photos shows the other side of the sleeve appears to be alittle worse. at any rate, a bore job/new piston will have it running good again. personally i would take a dremel to that cylinder before assembling it again, thats just me though.britincali wrote:Looks stock to me
typically heres what honda does, they quickly run a grinder over all the ports to take off the big edges if the sleeve isnt perfectly aligned
- 87CR500Rider
- Posts: 168
- Joined: January 4th, 2008, 7:47 am
- Location: San Antonio, TX
Thanks for the input. The bike was rich as you can see. It was that way when I got it. It is jetted correctly now. I probably put about 10 hours time on it since I got it and that's being generous. I've had it for about a year. Basically I was getting it running, saving money, finding parts, stuff like that. I have no idea of the history of the bike but the crank WILL be replaced. It "feels" tight but I'd feel alot better knowing it's got a new one in it. I mean, who knows what it's been through. You guys see what I'm talking about with the sleeve. It just looks weird to me. None of the ports line up. If you stick your finger in there, you can feel a ridge. A good sized ridge. That's got to be robbing some power. The cylinder measures a hair over 89mm so it's a stock bore. My plan is to send the topend to GSS and have it bored.
100hp honda you got way better eyes then I do. I understand what you're saying but I just don't see it in the pic?? It looks fine to me?100hp honda wrote:You can see where the sleeve doesnt match real well into the transfer.
I'm not a CR500 veteran by any stretch of the imagination. I've only rebuilt four late model CR500s including my own. And honestly they were all like this. I have always been suspect of the port alignment and assumed that matching these ports during machining was responsible for a good deal of the post engine performance. I can tell you my motor right now does not have very well matching ports. And it's of course a stock motor as were the others I've wrenched on.87CR500Rider wrote:It just looks weird to me. None of the ports line up. If you stick your finger in there, you can feel a ridge. A good sized ridge.
'03 CR500 powered by...umm...a new motor?
- britincali
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- britincali
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you cant see the sleeve sticking past the transfer area about 1/16" ? either hondas qaulity control in 1988 was shit, or someone did a shitty re-sleeve. ive examined several newer model stock cylinders and they had the ports matched pretty well.... considering they were done on a mass production assembly lineMICK wrote:100hp honda you got way better eyes then I do. I understand what you're saying but I just don't see it in the pic?? It looks fine to me?100hp honda wrote:You can see where the sleeve doesnt match real well into the transfer.
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ive had 2 bikes with stock cylinders, and ive bought another spare stock cylinder....all things considered, the ports were matched pretty well to the sleeves in all my experiences, maybe your experiences have been different. heres another photo of a stock jug... you can see the grind marks, they match the cylinder to the sleeve right at the factory
if you cant see these grinds marks, you definatly need glasses
if you cant see these grinds marks, you definatly need glasses
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90cr500guy wrote:...If you can see that from that pic, then you must be able to tell what color panties all the women you see on the street are wearing.
I can see the quick grinding done to your exhaust port as mine looks similar. But I can't tell a 1/16" inch from photos. But my jug does have several port edges with a 1-1.5mm raised lip as do others I've handled. Again it's another QC issue I believe stems from owning a motorcycle no longer in production. I don't doubt Honda stopped screening as many parts from production lines for the CR500 in the mid-late '90s. Parts that used to get rejected I'm sure were facilitated through the assembly line to save a penny. Production discrepancies are moderately common with these bikes from what I gather.
'03 CR500 powered by...umm...a new motor?
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bunch of old blind mofos around here. can you see this ?..its a camel toe ! you do know what a camel toe is right?90cr500guy wrote:I can not tell from that pic, how much difference there is in the height between the sleeve and the cylinder port.
If you can see that from that pic, then you must be able to tell what color panties all the women you see on the street, are wearing.
- teemtrubble
- Posts: 2269
- Joined: October 11th, 2007, 2:15 pm
- Location: simi valley, ca
Yes thank god I do! The one you got there looks like it needs rebuilt too. About 3" of slop right there isn't it?100hp honda wrote:...bunch of old blind mofos around here. can you see this ?..its a camel toe ! you do know what a camel toe is right?
http://www.youtube.com/watch?v=f2MqftlZyVM
"Your coochy, your flapper you're showing off your snapper. Your camel toe, it looks so right so baby let it go. Looooks like a big taco....
Last edited by MICK on October 11th, 2008, 5:32 pm, edited 1 time in total.
'03 CR500 powered by...umm...a new motor?
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i see what 100 hp is talking about but what does the other side look like??????? to me that sleeve looks stock!!!!! not every cyl cast is the same your going to get flaws here and there plus core shift. if it were a resleeve you would see the second sleeve in the OG, especally theres no grinding done to the cyl. when you resleeve you dont completly bore out the old sleeve you need some material to press the new one into
OH and nice TOE
OH and nice TOE
00'cr500 trailclimber
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92'cr500 hillclimber
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89'cr 500 bent frame
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93'cr500 beater
92'cr500 hillclimber
08,KTM SR500r hillclimber (conv)
89'cr 500 bent frame
04'crf230(wifeys)
02' cr125(sons)
02,pro jr 50 open exh. hill climber(sons)
02'sx65(sons)
03'xr50(sons)
- dannygraves
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- 87CR500Rider
- Posts: 168
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- Location: San Antonio, TX