El Cheapo piston ring compressor

FWYT
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FWYT
Edited Date/Time 2/10/2021 10:16am
Sometimes I'm all thumbs, even with a single ring piston, let alone on a four stroke piston.
Just tried this and it worked slick!!

Took a piece of PVC pipe smaller than the piston diameter. Notched it to allow it to slip across
the connecting rod and also to flex enough to gently fit over the piston and squeeze the ring.

Install the PVC ring over the piston and then you can hold the rings in place easily while you slide
the cylinder down. Then the PVC ring just slips out over the con rod.

One of the many things I wish I would have learned at 26 instead of 56. LaughingLaughingLaughing

Hope someone finds this useful!








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GoggleFiend904 11/30/2020 11:11am
11/30/2020 11:11am
I’m gonna try that. I don’t really have issues getting a cylinder on, but anything to make life easier is a plus in my book
4
kb228
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kb228 11/30/2020 12:07pm
11/30/2020 12:07pm
Sounds good but my luck id still have my oil ring pop out
2
mx5471
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mx5471 11/30/2020 12:18pm
11/30/2020 12:18pm
This method works great on a 4 stroke. Did it all the time. Install one circlip in the piston. Then install the rings on the piston with the proper orientation. Turn the cylinder upside down on the bench, and install the piston into the cylinder, Keep the wrist pin hole showing. Then with piston installed in cylinder, align the connecting rod and install wrist pin, then other circlip. Push the cylinder down, and good to go.
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Mr. Robinson 11/30/2020 12:45pm
11/30/2020 12:45pm
Great idea. I see a market for those.

When I was about 12 my dad showed me how to use a hose clamp to compress the rings to install the cylinder. Comes in handy ever now and then.
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garagedog
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garagedog 11/30/2020 4:41pm
11/30/2020 4:41pm
Looks like a good 3D printing idea.
-thanks
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SoCalMX70
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SoCalMX70 11/30/2020 7:52pm
11/30/2020 7:52pm
This is a fantastic idea! Don't need it for my YZ250 because the cylinder is designed to fantastically compress the rings as you slip it on, BUT... My 89 JS550 (Kawi Jetski) is an absolute PITA to get the cylinder on, further compounded that you have to deal with 2 holes. I'll be employing this method for the next top end refresh!
1
slipdog
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slipdog 11/30/2020 8:49pm
11/30/2020 8:49pm
How many base gaskets do you have stacked up there?
2
FWYT
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FWYT 11/30/2020 9:23pm
11/30/2020 9:23pm Edited Date/Time 11/30/2020 9:24pm
slipdog wrote:
How many base gaskets do you have stacked up there?
Slip Dog with the eye!! I was waiting for someone to mention it. Laughing Gotta few in there. I'll tidy it up when I set the final squish. Goofing around with some settings. Will report back soon-ish.
FWYT
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FWYT 11/30/2020 9:26pm
11/30/2020 9:26pm
SoCalMX70 wrote:
This is a fantastic idea! Don't need it for my YZ250 because the cylinder is designed to fantastically compress the rings as you slip it on...
This is a fantastic idea! Don't need it for my YZ250 because the cylinder is designed to fantastically compress the rings as you slip it on, BUT... My 89 JS550 (Kawi Jetski) is an absolute PITA to get the cylinder on, further compounded that you have to deal with 2 holes. I'll be employing this method for the next top end refresh!
Glad it could help out yourself, and others.
slipdog
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slipdog 11/30/2020 10:03pm
11/30/2020 10:03pm
slipdog wrote:
How many base gaskets do you have stacked up there?
FWYT wrote:
Slip Dog with the eye!! I was waiting for someone to mention it. :laugh: Gotta few in there. I'll tidy it up when I set the...
Slip Dog with the eye!! I was waiting for someone to mention it. Laughing Gotta few in there. I'll tidy it up when I set the final squish. Goofing around with some settings. Will report back soon-ish.
Haha, was just wondering what you had going on. I have my boy's 65 with 2 gaskets to make .8 total. I wanted a little more top end to help him pull longer and I cut the head .015" to get my squish back, He couldn't tell the difference, lol
1
FWYT
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FWYT 11/30/2020 10:28pm
11/30/2020 10:28pm Edited Date/Time 11/30/2020 10:50pm
slipdog wrote:
How many base gaskets do you have stacked up there?
FWYT wrote:
Slip Dog with the eye!! I was waiting for someone to mention it. :laugh: Gotta few in there. I'll tidy it up when I set the...
Slip Dog with the eye!! I was waiting for someone to mention it. Laughing Gotta few in there. I'll tidy it up when I set the final squish. Goofing around with some settings. Will report back soon-ish.
slipdog wrote:
Haha, was just wondering what you had going on. I have my boy's 65 with 2 gaskets to make .8 total. I wanted a little more...
Haha, was just wondering what you had going on. I have my boy's 65 with 2 gaskets to make .8 total. I wanted a little more top end to help him pull longer and I cut the head .015" to get my squish back, He couldn't tell the difference, lol
Yeah, I'm doing that same sort of thing but the impetus was to bring the cylinder up so that the transfers fully open;
so that at BDC, the bottom of the transfers are flush with the top of the piston. Because it seems like the charge coming in shouldn't be disrupted by the piston, at least at BDC. I'm having the head cut and will set the squish properly and will just have to see how the altered port timing changes things, as well.

Started here: https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/How-much-base-gas…

Probably changing too many things at one time to fully be able to tell what did what but you know how that saying goes- "Hey, since I have it apart . . . . " hahahhaha
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Tracktor
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Tracktor 12/2/2020 10:32am
12/2/2020 10:32am
slipdog wrote:
How many base gaskets do you have stacked up there?
FWYT wrote:
Slip Dog with the eye!! I was waiting for someone to mention it. :laugh: Gotta few in there. I'll tidy it up when I set the...
Slip Dog with the eye!! I was waiting for someone to mention it. Laughing Gotta few in there. I'll tidy it up when I set the final squish. Goofing around with some settings. Will report back soon-ish.
slipdog wrote:
Haha, was just wondering what you had going on. I have my boy's 65 with 2 gaskets to make .8 total. I wanted a little more...
Haha, was just wondering what you had going on. I have my boy's 65 with 2 gaskets to make .8 total. I wanted a little more top end to help him pull longer and I cut the head .015" to get my squish back, He couldn't tell the difference, lol
I had '12 KTM 65 that the PO had built a stroker 80cc engine for. IIRC, I had to stack 4 base gaskets to get squish right. I kept one of the old stacks for posterity. Never had an issue with it............
1
FWYT
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FWYT 12/9/2020 8:18am
12/9/2020 8:18am
Muscle-Milk-KTM wrote:
Been using these for years. [img]https://p.vitalmx.com/photos/forums/2020/12/09/464326/s1200_2F32F408_1C51_419B_9840_17DF07BE8413.jpg[/img]
Been using these for years.


Oh, sweet!! Where did you get that one?
1
Muscle-Milk-KTM 12/9/2020 8:36am
12/9/2020 8:36am
Muscle-Milk-KTM wrote:
Been using these for years. [img]https://p.vitalmx.com/photos/forums/2020/12/09/464326/s1200_2F32F408_1C51_419B_9840_17DF07BE8413.jpg[/img]
Been using these for years.


FWYT wrote:
Oh, sweet!! Where did you get that one?
I work a for hire (rental) company that rents out construction equipment. I’m doing pot & pistons on cut offs saws all day long, Husqvarna & Stihl’s mainly. This is a Husqvarna one. My company bought it from Husqvarna direct, you’ll probably find the same thing on EBay, it comes with different size ring compressers but this one fits my YZ125 piston just right.
1
FWYT
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FWYT 12/9/2020 8:59am
12/9/2020 8:59am
Muscle-Milk-KTM wrote:
I work a for hire (rental) company that rents out construction equipment. I’m doing pot & pistons on cut offs saws all day long, Husqvarna &...
I work a for hire (rental) company that rents out construction equipment. I’m doing pot & pistons on cut offs saws all day long, Husqvarna & Stihl’s mainly. This is a Husqvarna one. My company bought it from Husqvarna direct, you’ll probably find the same thing on EBay, it comes with different size ring compressers but this one fits my YZ125 piston just right.
Got it! Thanks!!

https://www.ebay.com/itm/Stens-751-045-Plastic-Ring-Compressor-Kit-Comp…

My bubble is burst for my genius device, though. Laughing
LaughingLaughing
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Mr. Robinson 12/9/2020 3:08pm
12/9/2020 3:08pm
FWYT wrote:
Got it! Thanks!!

https://www.ebay.com/itm/Stens-751-045-Plastic-Ring-Compressor-Kit-Comp…

My bubble is burst for my genius device, though. Laughing
LaughingLaughing
Honestly, I think yours is better. You don't have to hold it so you can use both hands to fit the jug. I'm just mad because I didn't think of it. Angry

I'm going to make one out of Delrin round stock that will have a tapered top edge to match the bottom of my cylinder so it won't let the ring go until it's totally inside the bore.
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FWYT
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FWYT 12/9/2020 9:27pm
12/9/2020 9:27pm
Mr. Robinson wrote:
Honestly, I think yours is better. You don't have to hold it so you can use both hands to fit the jug. I'm just mad because...
Honestly, I think yours is better. You don't have to hold it so you can use both hands to fit the jug. I'm just mad because I didn't think of it. Angry

I'm going to make one out of Delrin round stock that will have a tapered top edge to match the bottom of my cylinder so it won't let the ring go until it's totally inside the bore.
That sounds awesome! Please post it when you finish. That's a great idea about matching the taper.
I'm going to borrow that idea if you don't mind, though I'll have the low budget version.Smile
1
Mr. Robinson 12/10/2020 7:23am
12/10/2020 7:23am
Yeah, I'll post it up when done. I'm going to start with a 66mm version. I figure I'll make it a little smaller in I.D. so I get good ring compression. What do you think?

And by all means feel free to try the taper. I mean I'm copying your idea so how could I mind. Blush
2
Mr. Robinson 12/10/2020 9:57am
12/10/2020 9:57am
This is version 1.0 and although it does seem to work, I'm not real happy with it. I going to have to change the way I cut it out to use the Delrin and I'm not so sure it's the right material for this application. It seems to be a little too soft. I cut it from a slug and once I got the center cut out it got to flimsy to turn correctly and began to slip in the jaws and that's where the problems started. I need to try another one with a slightly longer slug and not cut the center all the way thought so it holds truer. Then use a cut off tool to separate the part from the base piece. PVC may be a better way to go. It's a lot stiffer. Once cut, this can be bent around fairly easy and isn't providing the tension I'd like to see on the rings.I'll just have to try another one.


1
FWYT
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FWYT 12/21/2020 9:59pm
12/21/2020 9:59pm Edited Date/Time 12/21/2020 10:01pm
Mr. Robinson- finally got around to putting things together again. Didn't bevel the edge, as the KTM cylinder doesn't really have one, but wanted to pass on another tip. My original inclination was to put the gap of the PVC so you could see the ring gap and make sure the locating pins are proper, as shown in the original post. But the usual place for the ring to catch on assembly is right at that spot where the ring ends tend to stick out.

So first I squeezed the rings with my fingers to locate them, then made a reference mark on the side of the piston and ring. Then, put on the ring compressor gently with full contact over the pin area and the open area on the reference marks. Hope that makes sense? Just gives a little peace of mind that things are proper and the cylinder slides on even easier.



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Million121
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Million121 2/9/2021 3:31pm
2/9/2021 3:31pm
Fwyt, i like your idea, can you mark and drill a hole to see the pins and ring ends?
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FWYT
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FWYT 2/9/2021 7:00pm
2/9/2021 7:00pm
Million121 wrote:
Fwyt, i like your idea, can you mark and drill a hole to see the pins and ring ends?
Yeah, that sure seems like it would work! Excellent idea!!!
2
Mr. Robinson 2/10/2021 10:14am
2/10/2021 10:14am Edited Date/Time 2/10/2021 10:16am
Holes would be a good idea. And maybe even 3D printing as someone suggested.

Yeah, I've dropped the ball on this. Got busy with other stuff and haven't got back around to it. I need to get some stiffer material and see what I can do with it, but your basic design is going to be hard to beat.

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