KX Riders
Maintenance & Technical => KX500 Original => Topic started by: jigggawatt on March 03, 2007, 12:37:49 PM
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I pulled my motor apart today. This is what I found. It ran good and the cylinder feels smooth. Should I have it replated ? If so who should I have do the work? What else should I have done to it while apart? The piston looks washed out on one side . What would've caused this?
Thanks,Jim
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The piston is done throw it in the trash and order new topend kit. The clyinder doesn't look bad at all. You can still see the cross hatch in the clyinder walls. Check for cracks around the ports, check the plating around the port openings to see if is chipped away, A ball hone can clean up that clyinder if there is no scoring. Looks like light scratches in the cylinder and no alumn. transfer. If you question the clyinder have it replated by lukesracing.com. From the photo's I would ball hone it and run with it. How's the lower end of the engine? Does the crank roll over smooth?
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I agree with Hughes regarding the piston, trash it. With regard to the ball hone, you shouldn't use a ball hone on a plated 2 stroke cylinder, the balls fall in the ports and due to the design of the hone they jump out and slap the cylinder, this can cuse the plating to fail. Wiesco has flexible hones that do not have balls on the ends and are reccommended for 2 stoke cylinders. I would look around the exhaust port, that seems to be the first place the plating starts to flake, there was a spot on one of the photos that looked like aluminum showing, check it real good.
Plated Cylinders: (Includes nickel ceramic coatings (Nikasil), chrome, Electrofusion, and boron composite.) If the plated cylinder is in good
condition, honing may not be necessary. If deglazing is necessary, DO NOT use a ball hone. Use a rigid or brush type diamond hone. Plated
cylinders cannot be bored oversize without replating or resleeving.
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Thanks I give lukes a shot . I just split the cases and put new crank seals in, bearings are ok.
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I only use ball hones in a 4-stroke with no ports. On plated cylinders I like to hone by hand with some 400 wet & dry and wd40. That way I can concentrate on the areas that need it but remove only the minimum material possible. It's easy to get a nice cross hatch by hand. Cam.
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I agree with Hughes regarding the piston, trash it. With regard to the ball hone, you shouldn't use a ball hone on a plated 2 stroke cylinder, the balls fall in the ports and due to the design of the hone they jump out and slap the cylinder, this can cuse the plating to fail. Wiesco has flexible hones that do not have balls on the ends and are reccommended for 2 stoke cylinders. I would look around the exhaust port, that seems to be the first place the plating starts to flake, there was a spot on one of the photos that looked like aluminum showing, check it real good.
Plated Cylinders: (Includes nickel ceramic coatings (Nikasil), chrome, Electrofusion, and boron composite.) If the plated cylinder is in good
condition, honing may not be necessary. If deglazing is necessary, DO NOT use a ball hone. Use a rigid or brush type diamond hone. Plated
cylinders cannot be bored oversize without replating or resleeving.
I agree that a ball hone might cause an issue with plated clyinders. I have used them in my plated cylinders with great results. The key is getting the correct size hone, and speed in which you trun the hone, and the grit. My only fear has been that the ball hone my chip the plating on one of the port edges. If a 2-stroke engine has sleeves installed then a ball is great with no ill effects. I have tried KXCAMM22's method and it works. I like the results that those brush style hone give you.
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Hughes is exactly right a ball hone can chip the edges of the ports, wiseco has really trick hones that eliminate issues with chipping, but are flexible. A rigid hone works well also, not the spring loaded types purchased at a local auto parts store, but something on the order of a sunnen hone. I'm not sure I would do the sandpaper and wd40 deal, I guess it would sork but the whole idea is to maintain a uniform cross hatch pattern around the cylinder.
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I have seen the results of those brush style hones and it's cool. I just have not used them myself. These things look like a brush and it de-glazes the cylinder a lays down a nice cross hatch. I'll if I can find one on-line. Lukesracing.com will clean and hone the cylinder for around 50.00
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http://www.coolskunk.com/Two%20stroke%20into.htm
Scroll down to: Honing the clyinder bore. Eric Gorr uses ball hones on his 2-stroke rebuilds.
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I was wondering if anyone has redone the top end and not had the cylinder re-plated? And, if so what happened?
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When I first got my 87 500 I replaced the top end and the plating was shot, it was not flaking off but was oil glazed and zero cross hatch was present. It ran great for almost a year then I rebuilt the engine from bottom to top including a replate. I took a gamble with my bike but it had no ill effects. If the bike is going to be your primary ride then re-plate the clyinder. The Nikasil is very hard stuff and will last almost forever with clean air fitlers and good oil. Do you have any damage to the clyinder walls?
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I havent taken a look yet, but I am planning to redo the bike over summer before next desert season. I to have a 1987 Kx500 and was amazed at how much my local shop wanted for the re-plating.
P.S: Thanks for the parts list for the 87' k5.
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Lukesracing.com charges 150.00. Check them out. They did mine last year. Hope the parts list helps you out on finding some parts.
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$150?? WOAH!!!!
I haven't looked inside mine either yet but from the exhaust port it looks ok. Is there any way to hone Nikisel without ruining your cylinder?
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I merged another topic where we talked about honing plated cylinders. scroll back up and read through the post.
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The proper method for honing a 2t cylinder is to use a rigid hone such as a sunnen (expensive) or a diamond brush type hone, about $50. While there has been much discussion on whether to use a ball hone or not, I wouldn't. The plating is very hard but it can chip causing the cylinder to fail.
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I just got my cylinder back today. I couldn't get ahold of Lukes so I sent it of to Millennium. Fast turn around 194.00 with shipping