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How to slide the cylinder over the piston?

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:bonk:Took my cylinder off to inspect the piston and rings on a used KTM, now trying to put back together but having a hard time getting the cylinder over the rings. Any tips? Do I need a sleeve like tool?

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I find it easier to take the piston off the rod and slip the piston and rings into the cylinder just enough to leave the wrist pin hole exposed then slip the entire thing onto the rod and push the pin back through. Replace the one clip you removed and slide in down.

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You really should be able to squeeze the 2 rings by hand while dropping the cylinder down over the piston. It can be really handy to have a buddy come over and assist with this..

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I get it kinda in position, then hold the rings with 2 fingers, PITA, but eventually will work. Have you tried drinking alot of beer first?? Helped me.

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You really should be able to squeeze the 2 rings by hand while dropping the cylinder down over the piston. It can be really handy to have a buddy come over and assist with this..

^^^

Having a friend help makes it much easier until you get the hang of it. And as also said, make sure the rings are positioned on the piston correctly.

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I use a piece of wood. It is just wide enuf to fit between the studs and rest flat on top of the cases. It has a cut-out for the rod. It is a bsaic U shape. Easy to make out of 1/4" ply. The bottom of the piston rests on it and keeps the piston square and wiggle free. Then you can just concentrate on holding the rings with your fingers tips and the weight of the cyl will just about be enuf for it to drop on.

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Have a girl do it for you. 👍🙂 I didn't use wood or any other fancy tools... just my two hands. One to hold the cylinder, one to squeeze the rings and hold the piston. Easy peasy. Yep, I truly think it's a girl thing... at least let her guide it in for ya! 🤣:applause:

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Tip the cylinder slightly forward and get it over the front half of the top ring. Now that the front is held in, squeeze the open end of the ring together and tilt the cylinder over it and so it slips over the whole ring. Repeat for ring #2 if applicable.

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zip tie the rings tight. lube the cylinder and piston and slide it on. as the cylinder lowers it will push the zip ties down just cut them off before you lower the cylinder all the way down. but only do this if you cant just squeeze the rings by hand.

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Putting all those ideas together:

Make the wooden tool. I usually skip this. It is faster to skip it for me then to stop and make the tool, but with the tool it goes much easier and since you don't have to hold the piston it is one less thing to hold. It already takes 3 hands and holding you mouth just right. Much easier, especially if doing this by yourself, with the tool. The tool is in the manual too.

Position the rings with the gaps over the locating pins in the piston.

Work the cylinder down on the piston noting that the front of the cylinder hangs down further then the back so it goes over the rings first. Use it to hold the rings compressed in the front while you work the rings in on the side and back. Work the rings around from front to back. Since the front skirt of the cylinder hangs lower then the back use the front cyl skirt to hold the rings compressed in the front while you work the rings in on the sides and back. Do this by holding the piston pushed forward into the cylinder skirt. Keep an eye on the ring gaps in the back to make sure a ring is not pushed out of the groove and broken and also that the gap is located over the locating pin in the piston as they come down into the groove.

The bigger the bike (piston diameter) the easier this is to accomplish IMO.

You can do this by yourself, but to do so you have to hold the rings compressed on the sides and back openings of the cylinder skirt with part of you fingers on each hand on rings on the sides, some fingers on the rings in the back back and some more fingers and palm of the hand on the cylinder to ease it down over the piston.

I use one hand in the front, reaching around to compress the rings on the sides with my thumb and middle fingers, one on each side, with my forefinger on the cylinder on the other side and the top side of by first knuckle and palm in the front to position the cylinder up and down. With the other hand reaching around from the back with my thumb and middle finger compressing the rings and my forefinger to position the back of the cylinder up and down. I think.

Having the girl help is a good idea. You don't need to push down on the cylinder, but more like let it down. If is isn't going down something is wrong like the rings are coming out of the groves, they are not positioned over the locating pins, or the cylinder is not aligned with the piston (coming down cocked). It is hard to judge alignment since the piston engages the front of the cylinder first and then the back. This helps with compressing the rings but makes aligning the piston into the cylinder harder.

It is easier to get the piston in the cylinder with it on the bench, leaving the piston pin to be installed as mentioned. However, it is harder to get the piston pin retainer clip in with the cylinder in the way IMO. Much easier this way if you have a clip installation tool. http://www.buxtools.com/product_catalog.php How it works: http://www.docstoc.com/docs/5718390/Introducing-the-C-Clipper-The-one-shot-installer-for I don't have one. I use a very small screwdriver with a notch ground in the shoulder.

When you accomplish this for the first time you will receive the gift of total consciousness. Others have died trying to gain this. On a more basic note you will also realize what separates us (humans) from the animals. However, like sex, it is only a fleeting moment so later on you may start to take it for granted

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:bonk:Took my cylinder off to inspect the piston and rings on a used KTM, now trying to put back together but having a hard time getting the cylinder over the rings. Any tips? Do I need a sleeve like tool?

Make sure your rings are over the index pins, these keep the rings from rotating and end gaps ending up over a port. Just slip the cylinder onto the studs, squeeze the rings lightly with your fingertips and gently slide the cylinder down. Dont force anything.

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Okay, I get all the jokes, I figured this should be simple but it is my first time. Can anyone tell me how to determine where these "index pins" are located?

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They are in the back of the piston inside the ring grooves. They locate the rings and keep them form rotating around the piston so the gaps can never be located inside a port. You can see the pins or slide the end of a ring in the groove and feel them.

If any other part of the ring is over the pin, other then the end gap, when you try to slide the piston into the cylinder the pin will hold the ring out of the groove. With the ring forced out of the groove you can't get the cylinder on, or if you do you will break a ring in the process.

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A large hose clamp is a good make shift ring compressor. Tighten up enough to compress the rings but loose enought to slide out of the way when you push the cylinder down over the piston.

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Have a girl do it for you. 👍🙂 I didn't use wood or any other fancy tools... just my two hands. One to hold the cylinder, one to squeeze the rings and hold the piston. Easy peasy. Yep, I truly think it's a girl thing... at least let her guide it in for ya! 🤣:applause:

That last sentence is the key....always good advice...for any situation...lol.

Im always paranoid about having the rings sitting over the locating pin, to the point where I'll pull the cylinder back up & redo it a couple times, just to check myself.

I dont think its realistically possible to get a ring stuck....& surely you would feel it when you turn the engine over before bolting it back up....but you never know I guess.....if in doubt have another beer??

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