CR125 chipped cylinder

king_halsey
Posts
11
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2/27/2019
Location
Broken Arrow, OK US
2/27/2019 11:19am Edited Date/Time 2/28/2019 8:20pm
Hello, I recently bought a 96 CR125. It was running but the motor locked so I rebuilt everything. The cylinder sleeve and piston showed signs of metal or dirt floating around, so I honed the cylinder, put in a new piston kit. I've cleaned everything and everything looks good. However, on the bottom of the cylinder jug, there's a chip of it missing (previous owners probably tried to redneck resleeve it) and it was crumbling a little bit. I did my best to grind it smooth, I'll probably have to do it again. I have a picture of it before I buffed it. My question is, should I just get another cylinder jug? Or can I grind it flat and be good? I understand I have to be careful that I don't touch the gasket surface or it won't seal. It has a piston sleeve so I don't think it will affect the piston..
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Hondas4Life3
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853
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7/30/2013
Location
Louisburg, KS US
2/27/2019 11:23am Edited Date/Time 2/27/2019 11:26am
Hello, I recently bought a 96 CR125. It was running but the motor locked so I rebuilt everything. The cylinder sleeve and piston showed signs of...
Hello, I recently bought a 96 CR125. It was running but the motor locked so I rebuilt everything. The cylinder sleeve and piston showed signs of metal or dirt floating around, so I honed the cylinder, put in a new piston kit. I've cleaned everything and everything looks good. However, on the bottom of the cylinder jug, there's a chip of it missing (previous owners probably tried to redneck resleeve it) and it was crumbling a little bit. I did my best to grind it smooth, I'll probably have to do it again. I have a picture of it before I buffed it. My question is, should I just get another cylinder jug? Or can I grind it flat and be good? I understand I have to be careful that I don't touch the gasket surface or it won't seal. It has a piston sleeve so I don't think it will affect the piston..
Looks like the sleeve is off center/rotated. That cylinder is trash and if they ground on the power valve those too. Look for a non-sleeved used cylinder or new OEM.
3
king_halsey
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11
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2/27/2019
Location
Broken Arrow, OK US
2/27/2019 11:34am
Hello, I recently bought a 96 CR125. It was running but the motor locked so I rebuilt everything. The cylinder sleeve and piston showed signs of...
Hello, I recently bought a 96 CR125. It was running but the motor locked so I rebuilt everything. The cylinder sleeve and piston showed signs of metal or dirt floating around, so I honed the cylinder, put in a new piston kit. I've cleaned everything and everything looks good. However, on the bottom of the cylinder jug, there's a chip of it missing (previous owners probably tried to redneck resleeve it) and it was crumbling a little bit. I did my best to grind it smooth, I'll probably have to do it again. I have a picture of it before I buffed it. My question is, should I just get another cylinder jug? Or can I grind it flat and be good? I understand I have to be careful that I don't touch the gasket surface or it won't seal. It has a piston sleeve so I don't think it will affect the piston..
Looks like the sleeve is off center/rotated. That cylinder is trash and if they ground on the power valve those too. Look for a non-sleeved used...
Looks like the sleeve is off center/rotated. That cylinder is trash and if they ground on the power valve those too. Look for a non-sleeved used cylinder or new OEM.
So I should just get rid of the cylinder core and get a new one? I prefer sleeving so if something screws up I can hone it instead of nikasil coating, I have all the stuff needed to do sleeving jobs.
As for the power valve I rebuilt that too, one of the sliding valve sleeves is cracked so that valve sticks, I'll need to replace that
1
Hondas4Life3
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Louisburg, KS US
2/27/2019 12:36pm Edited Date/Time 2/27/2019 12:39pm
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is properly rebuilt and maintained a nikasil cylinder will last longer on the bore and have better heat transfer.
3
king_halsey
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11
Joined
2/27/2019
Location
Broken Arrow, OK US
2/27/2019 12:56pm
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is...
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is properly rebuilt and maintained a nikasil cylinder will last longer on the bore and have better heat transfer.
Alright, I will do that. Where's the cheapest place to have a cylinder nikasil recoated?

The Shop

Paul_Pitzonka
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693
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5/1/2018
Location
Grand Terrace, CA US
2/27/2019 1:30pm
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is...
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is properly rebuilt and maintained a nikasil cylinder will last longer on the bore and have better heat transfer.
Alright, I will do that. Where's the cheapest place to have a cylinder nikasil recoated?
I’ve used power seal and millennium technologies... both put out excellent work... I stick with powerseal now because they are a little cheaper also they do a beautiful job chamfering the ports on a two stroke
1
Paw Paw 271
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Benton, LA US
2/27/2019 3:00pm Edited Date/Time 2/27/2019 3:01pm
That looks like very poor workmanship to me.

Paw Paw
2
king_halsey
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11
Joined
2/27/2019
Location
Broken Arrow, OK US
2/27/2019 3:10pm
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is...
Yes new cylinder. A nikasil cylinder is superior to a sleeved cylinder. There is a reason manufactures went away with lined cylinders. If the engine is properly rebuilt and maintained a nikasil cylinder will last longer on the bore and have better heat transfer.
Alright, I will do that. Where's the cheapest place to have a cylinder nikasil recoated?
I’ve used power seal and millennium technologies... both put out excellent work... I stick with powerseal now because they are a little cheaper also they do...
I’ve used power seal and millennium technologies... both put out excellent work... I stick with powerseal now because they are a little cheaper also they do a beautiful job chamfering the ports on a two stroke
I'll look into that. I also found a nickel coating place nearby, or I could buy a cylinder that's already been coated. Thanks everyone for the input, you probably saved me a lot of tears and regret
king_halsey
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2/27/2019
Location
Broken Arrow, OK US
2/27/2019 3:12pm
That looks like very poor workmanship to me.

Paw Paw
They clearly hammered it in or something instead of doing it properly ?
speed_racer
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Aiea, HI US
Fantasy
2104th
2/28/2019 5:49pm
You can not plate a sleeved cylinder with Nikasil. You will need a new cylinder and piston to do the repair correctly.
Do not waste any money trying to get a new sleeve installed. The cylinder is trash.
It's also a bad idea to buy a bad cylinder on eBay that needs plating. Once Millenium receives a cylinder they often need to weld cracks, plating is usually 150/200. Those 1996 cylinders have been discontinued for many years. Most likely you'll have to buy a used cylinder that needs plating. Call Millenium and see if they have a cylinder for sale. Also, call LA sleeve for a cylinder. DO NOT LET LA SLEEVE TALK YOU INTO ANOTHER SLEEVED CYLINDER, THEY WILL TRY.
The CR125 hates sleeved cylinders. They seize easily if you don't run the jetting rich. I'd buy this one quick.
With the cylinder and power valves, this is a good deal.

ebay
1
king_halsey
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2/27/2019
Location
Broken Arrow, OK US
2/28/2019 7:21pm
You can not plate a sleeved cylinder with Nikasil. You will need a new cylinder and piston to do the repair correctly. Do not waste any...
You can not plate a sleeved cylinder with Nikasil. You will need a new cylinder and piston to do the repair correctly.
Do not waste any money trying to get a new sleeve installed. The cylinder is trash.
It's also a bad idea to buy a bad cylinder on eBay that needs plating. Once Millenium receives a cylinder they often need to weld cracks, plating is usually 150/200. Those 1996 cylinders have been discontinued for many years. Most likely you'll have to buy a used cylinder that needs plating. Call Millenium and see if they have a cylinder for sale. Also, call LA sleeve for a cylinder. DO NOT LET LA SLEEVE TALK YOU INTO ANOTHER SLEEVED CYLINDER, THEY WILL TRY.
The CR125 hates sleeved cylinders. They seize easily if you don't run the jetting rich. I'd buy this one quick.
With the cylinder and power valves, this is a good deal.

ebay
Funny you say that, I had to rebuild the engine BECAUSE it seized while I was adjusting the carb ? not a good day
I'll call and see if they have cylinders, I just gotta scrounge up the money to buy one. Everyone here has pretty much talked me out of cylinder sleeves so I'll get a plated one.
BR8ES
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6/3/2018
Location
Bennett, CO US
2/28/2019 8:06pm
iron sleeves can be plated, CR500s get it quite often, as do vintage bikes, etc.
2
king_halsey
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Broken Arrow, OK US
2/28/2019 8:12pm
BR8ES wrote:
iron sleeves can be plated, CR500s get it quite often, as do vintage bikes, etc.
I wasn't going to plate a sleeve I didn't even know anyone could do that. I've only heard to hone them if they're scuffed
BR8ES
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1914
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Location
Bennett, CO US
2/28/2019 8:18pm
BR8ES wrote:
iron sleeves can be plated, CR500s get it quite often, as do vintage bikes, etc.
I wasn't going to plate a sleeve I didn't even know anyone could do that. I've only heard to hone them if they're scuffed
I had mine done, many others have as well. Not trying to sell that to you, just saying it is done. If you can find a proper cylinder and have it bored/replated, that would be wise.
king_halsey
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11
Joined
2/27/2019
Location
Broken Arrow, OK US
2/28/2019 8:20pm
BR8ES wrote:
iron sleeves can be plated, CR500s get it quite often, as do vintage bikes, etc.
I wasn't going to plate a sleeve I didn't even know anyone could do that. I've only heard to hone them if they're scuffed
BR8ES wrote:
I had mine done, many others have as well. Not trying to sell that to you, just saying it is done. If you can find a...
I had mine done, many others have as well. Not trying to sell that to you, just saying it is done. If you can find a proper cylinder and have it bored/replated, that would be wise.
Yeah I'm gonna just get a new one that's been plated and try to sell that one. Maybe someone else can fix it and use it

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