300 kit installed/ initial results
#51
01-29-2007, 03:12 PM
RE: 300 kit installed/ initial results
I'm learning a bunch here!
TeamKLX250: Does the plating process add to the bore of a cylinder in the case of a rebore? For instance; If you were to bore a stock 250 cylinder .5mm and you were going to use a OEM cast .5mm os piston. Would you have to take into consideration the thickness of the plating when you bored the cylinder?
Inquiring minds need to know.
TeamKLX250: Does the plating process add to the bore of a cylinder in the case of a rebore? For instance; If you were to bore a stock 250 cylinder .5mm and you were going to use a OEM cast .5mm os piston. Would you have to take into consideration the thickness of the plating when you bored the cylinder?
Inquiring minds need to know.
#52
01-29-2007, 06:17 PM
RE: 300 kit installed/ initial results
ORIGINAL: vfrpilot
I'm learning a bunch here!
TeamKLX250: Does the plating process add to the bore of a cylinder in the case of a rebore? For instance; If you were to bore a stock 250 cylinder .5mm and you were going to use a OEM cast .5mm os piston. Would you have to take into consideration the thickness of the plating when you bored the cylinder?
Inquiring minds need to know.
I'm learning a bunch here!
TeamKLX250: Does the plating process add to the bore of a cylinder in the case of a rebore? For instance; If you were to bore a stock 250 cylinder .5mm and you were going to use a OEM cast .5mm os piston. Would you have to take into consideration the thickness of the plating when you bored the cylinder?
Inquiring minds need to know.
But that is something that has changed. You used to go into a OEM dealer & buy a larger piston requiring a rebore but now I dont think OEMs like Honda & Kawasaki make oversized pistons that you need to bore & replate. That is just the aftermarket. If anything at all the OEMs just have differnt piston & cylinder classes for manufacturing tolerance.Then they match tolerance classes of pistons & cylinders to each other. Like you may have an "A" cylinder that takes an "A" piston but would notreplace the piston in a "B" cylinder with a "D" piston. In short the OEMs dont want you to bore & replate. They want you to buy a new cylinder if yours is worn out or damaged.
Could you put a "D" psiton in an "A" cylinder? (assuming in this example the D is larger than the A to make up for a slightly worn bore, but not worn through the coating) Maybe, but they would not publish the measurements you would have to buy & try on your own.
EDIT I looked at a KLX 300 parts list & it seems they dont even have any different sizes for manufacturing tolerance. Just one size piston & one size cylinder (no overbores either). But I have seen other bikes with the cylinder-piston classes.
#53
01-29-2007, 07:49 PM
RE: 300 kit installed/ initial results
Not sure if this is the stuff because I had it sent out. I had a big bore Honda Arias piston and cylinder
sprayed with a coating, and the top of the piston coated with a ceramic. I would do the combustion chamber too. You just hone the coating to the the size you want. You can run them pretty tight too.
http://www.performancecoatings.com/enginecoatings.html
sprayed with a coating, and the top of the piston coated with a ceramic. I would do the combustion chamber too. You just hone the coating to the the size you want. You can run them pretty tight too.
http://www.performancecoatings.com/enginecoatings.html
#54
01-30-2007, 02:59 AM
RE: 300 kit installed/ initial results
Awesome, thanks! 
ORIGINAL: TeamKLX250
The Different Types of Steel-Lined and Plated Cylinders
There are two types of cylinder bores used on dirt bikes, steel or cast iron sleeves or ones with plating on the aluminum. Most dirt bikes made after 1989 have plated cylinders. You can check a cylinder with a magnet. If it sticks to the bore then it is a sleeve. If it doesn't stick then it is plated. There are three types of plated cylinders, Kawasaki Electrofusion, hard-chrome, and nickel silicon carbide. There are several variations of the nickel silicon carbide process but the most common trade name is Nikasil. The nickel-based processes have many advantages over hard-chrome, Electrofusion, and sleeving. Nickel attracts oil and is an excellent carrier material for silicon carbide particles, a wear resistant material that carries the load of the piston. This material is electro-plated right on to the aluminum cylinder for the optimum thermal efficiency. Nickel can be honed with diamond stones which leave distinctive peaks and valley scratches in the cylinder wall which retain oil and provide a certain bearing ratio between the running surfaces of the bore. It's possible to rebuild a plated cylinder by fitting it with a sleeve. However you can expect to pay more for bore maintenance over the life of the bike, and lose thermal efficiency and horsepower. Plated cylinders are harder and last longer than sleeved cylinders. Kawasaki cylinders with the original Electrofusion coating or hard-chromed cylinders can be repaired with nickel plating or sleeving. Steel or cast iron sleeves cannot be nickel plated unless they are separated from the aluminum cylinder. The reason is that the pretreatment for the plating would disintegrate the aluminum. There are four companies that replate cylinders in the USA. The average price to replate a cylinder is about $200.
ref: http://www.off-road.gr/News-article-...de-thread.html
The Different Types of Steel-Lined and Plated Cylinders
There are two types of cylinder bores used on dirt bikes, steel or cast iron sleeves or ones with plating on the aluminum. Most dirt bikes made after 1989 have plated cylinders. You can check a cylinder with a magnet. If it sticks to the bore then it is a sleeve. If it doesn't stick then it is plated. There are three types of plated cylinders, Kawasaki Electrofusion, hard-chrome, and nickel silicon carbide. There are several variations of the nickel silicon carbide process but the most common trade name is Nikasil. The nickel-based processes have many advantages over hard-chrome, Electrofusion, and sleeving. Nickel attracts oil and is an excellent carrier material for silicon carbide particles, a wear resistant material that carries the load of the piston. This material is electro-plated right on to the aluminum cylinder for the optimum thermal efficiency. Nickel can be honed with diamond stones which leave distinctive peaks and valley scratches in the cylinder wall which retain oil and provide a certain bearing ratio between the running surfaces of the bore. It's possible to rebuild a plated cylinder by fitting it with a sleeve. However you can expect to pay more for bore maintenance over the life of the bike, and lose thermal efficiency and horsepower. Plated cylinders are harder and last longer than sleeved cylinders. Kawasaki cylinders with the original Electrofusion coating or hard-chromed cylinders can be repaired with nickel plating or sleeving. Steel or cast iron sleeves cannot be nickel plated unless they are separated from the aluminum cylinder. The reason is that the pretreatment for the plating would disintegrate the aluminum. There are four companies that replate cylinders in the USA. The average price to replate a cylinder is about $200.
ref: http://www.off-road.gr/News-article-...de-thread.html
#55
01-30-2007, 05:37 AM
RE: 300 kit installed/ initial results
Now this is getting good. I have not played with coatings of the piston or cylinders before. Also good read TeamKLX250. But isn't .004" for a cast piston kinda large? As an example, I bored and honed my zx7 with cast oem .5mm over pistons with steel liners to .0025" from a stock .0015".
#56
01-30-2007, 03:02 PM
RE: 300 kit installed/ initial results
I think(the key word) that piston / clyinder clearance is all proportional to the size of the bore. This is what I know: On a 2 stroke 350 with a exhaust bridge and a forged piston you need a minimum of .005 clearance. The bridge itself expands and can cause problems. However on my XL600 I'm using a OEM cast piston bored .5mm(.020) and Honda's recomended clearance is .008. But keep in mind that this is a 4" bore......that's a big piston. On smaller 4 strokes the clearance is considerably smaller. So I don't think that you can generalize the amount of clearance on all single cylinder engines. Depending on wheather they are 2 stroke, 4 stroke, and type of piston and size of bore.
This is just what I've picked up over the years. But please correct me if I'm wrong.
This is just what I've picked up over the years. But please correct me if I'm wrong.
#58
01-30-2007, 03:44 PM
RE: 300 kit installed/ initial results
That figure I threw out was from a Dirt Bike magazine article from SEVERAL years ago so it was assuming 2 stroke dirt bikes. & it listed those using the word "tolerate" as in the servive limit. I checked my RM125 manual & sure enough the service limit was .004. But ya, I agree it depends on the nature of the engine because I looked up in my old KZ550 4 cylinder manual & the clearance was actually alot tighter.
#59
01-30-2007, 10:25 PM
RE: 300 kit installed/ initial results
and this makes sense to me. Thanks for reminding/refreshing my memory of this.
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