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Damaged bore on a kdx200

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Are you talking about doing it yourself or having a shop do it? Either way, you may want to look into having it replated. I see you are in New Zealand, so you may want to look for a business such as this one:

http://www.mt-llc.com/

Generally, such businesses can do repair work on damaged cylinders as well. This is done before replating.

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Are you talking about doing it yourself or having a shop do it? Either way, you may want to look into having it replated. I see you are in New Zealand, so you may want to look for a business such as this one:

http://www.mt-llc.com/

Generally, such businesses can do repair work on damaged cylinders as well. This is done before replating.

I'm fixing the bike myself. Can you not just sleave the cylinder?

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Since you sound like you are wanting to install a sleeve yourself, then I will answer as such. There is no way in heck that you have all the equipment required to properly install a sleeve yourself. Sleeves are generally installed by machine shops. The various equipment needed is way beyond the common home mechanic's budget or skills.

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I'm fixing the bike myself. Can you not just sleave the cylinder?
Sure you can have the cylinder sleeved, but why? Re-plating doesn't cost much more, but is vastly superior. Sleeving a plated cylinder is like taking the fuel injection off of your brand new car and installing a carburetor. It will work, but it's a big step backwards.

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All comments are correct when considering performance and longevity.

A sleeve is inferior to plating.

However, there are times when repairing a cylinder for plating is not cost effective.

I would never say that you do not have the equipment, or access to the equipment required to sleeve the cylinder yourself.

I have watched it accomplished with a Vertical mill, oven, press, hone, and a dremel.

It was crude but it worked just fine.

I found this info at LA sleeve that really describes to process well:

Step 1. The cylinder must be stripped of all removable parts: studs, nuts, bolts, manifolds, etc.

Step 2. The cylinder is bored out to accept the sleeve. When the sleeve is installed into an all

aluminum cylinder, the interference fit is .004. When the sleeve is being installed into a

cast iron cylinder bore, the interference fit is .002 to .003.

The interference fit is determined by measuring the outside diameter of the sleeve, then

boring the cylinder diameter smaller than the sleeve.

The interference fit is a critical aspect of sleeve installation because this step insures

that the sleeve does not move when in the cylinder. Also, proper interference fit is

important for cylinder cooling purposes.

Step 3. The cylinder is then heated in an oven between 400o, up to 450o for an hour or more.

Do not use a torch or hot plate for this procedure. It is important that the cylinder heats

uniformly.

Step 4. The cylinder is then removed from the oven and the sleeve will drop easily into the cylinder.

Turning the sleeve by hand to line up the ports is a common practice, or you can use a

needle nose type device to align the ports.

You will have between five and ten seconds before the sleeve and cylinder lock up.

Step 5. The cylinder must then be put under a hydraulic press to keep the sleeve from rising while

the cylinder is cooling.

Step 6. The ports of the sleeve must then be blended with the cylinder by using an assortment of

hand grinding porting tools. Mismatched ports will cause some power loss to the engine.

Step 7. After the ports have been matched, the cylinder (sleeve) must be bored out and honed to

insure proper piston clearance.

Measure your piston at the skirt to properly bore the sleeved cylinder to the correct

bore size. Chamfer the edges of all the ports to prevent the rings from catching on a sharp

edge.

Next, hone your cylinder to the correct piston clearance.

Properly sleeved cylinders can use the O.E.M. recommended piston clearance. If you

have a doubt, add a half thousandth (.0005) to the clearance.

Step 8. As an added finishing touch, surface decking the top of the cylinder is recommended in

order to make sure that the head gasket will sit flat on the cylinder to create a good sealing

surface.

Make sure you only take the minimum cut off the top of the cylinder.

Moto

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Since you sound like you are wanting to install a sleeve yourself, then I will answer as such. There is no way in heck that you have all the equipment required to properly install a sleeve yourself. Sleeves are generally installed by machine shops. The various equipment needed is way beyond the common home mechanic's budget or skills.

No, I'm going to put the bike back together myself, but any sleaving or plating I would pay to get done. I was just wondering what choices I had to fix a damaged bore, and what were the pro's and con's.

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Plating is going to be superior to sleeving, unless the cylinder is damaged in such a way that welding/replating will be far to expensive. It does happen. In that case a sleeve may be a better alternative than looking for a replacement cylinder.

I have a pretty seriously gouged up cylinder at Langcourt right now. The quoted estimate before shipping it to them was very reasonable. I will let you know what the cost ends up being. There were probably 5 or 6 pretty deep gouges, several of them over one of the sub exhaust ports. IMO the cylinder was fit for the garbage can, but I thought I'd send it in and see what they can do for me.

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Plating is going to be superior to sleeving, unless the cylinder is damaged in such a way that welding/replating will be far to expensive. It does happen. In that case a sleeve may be a better alternative than looking for a replacement cylinder.

I have a pretty seriously gouged up cylinder at Langcourt right now. The quoted estimate before shipping it to them was very reasonable. I will let you know what the cost ends up being. There were probably 5 or 6 pretty deep gouges, several of them over one of the sub exhaust ports. IMO the cylinder was fit for the garbage can, but I thought I'd send it in and see what they can do for me.

Ok, thanks. Please let me know the final cost.

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All comments are correct when considering performance and longevity.

A sleeve is inferior to plating.

However, there are times when repairing a cylinder for plating is not cost effective.

I would never say that you do not have the equipment, or access to the equipment required to sleeve the cylinder yourself.

I have watched it accomplished with a Vertical mill, oven, press, hone, and a dremel.

It was crude but it worked just fine.

I found this info at LA sleeve that really describes to process well:

Step 1. The cylinder must be stripped of all removable parts: studs, nuts, bolts, manifolds, etc.

Step 2. The cylinder is bored out to accept the sleeve. When the sleeve is installed into an all

aluminum cylinder, the interference fit is .004. When the sleeve is being installed into a

cast iron cylinder bore, the interference fit is .002 to .003.

The interference fit is determined by measuring the outside diameter of the sleeve, then

boring the cylinder diameter smaller than the sleeve.

The interference fit is a critical aspect of sleeve installation because this step insures

that the sleeve does not move when in the cylinder. Also, proper interference fit is

important for cylinder cooling purposes.

Step 3. The cylinder is then heated in an oven between 400o, up to 450o for an hour or more.

Do not use a torch or hot plate for this procedure. It is important that the cylinder heats

uniformly.

Step 4. The cylinder is then removed from the oven and the sleeve will drop easily into the cylinder.

Turning the sleeve by hand to line up the ports is a common practice, or you can use a

needle nose type device to align the ports.

You will have between five and ten seconds before the sleeve and cylinder lock up.

Step 5. The cylinder must then be put under a hydraulic press to keep the sleeve from rising while

the cylinder is cooling.

Step 6. The ports of the sleeve must then be blended with the cylinder by using an assortment of

hand grinding porting tools. Mismatched ports will cause some power loss to the engine.

Step 7. After the ports have been matched, the cylinder (sleeve) must be bored out and honed to

insure proper piston clearance.

Measure your piston at the skirt to properly bore the sleeved cylinder to the correct

bore size. Chamfer the edges of all the ports to prevent the rings from catching on a sharp

edge.

Next, hone your cylinder to the correct piston clearance.

Properly sleeved cylinders can use the O.E.M. recommended piston clearance. If you

have a doubt, add a half thousandth (.0005) to the clearance.

Step 8. As an added finishing touch, surface decking the top of the cylinder is recommended in

order to make sure that the head gasket will sit flat on the cylinder to create a good sealing

surface.

Make sure you only take the minimum cut off the top of the cylinder.

Moto

Thats very informative, thanks

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