Caber vs Kolbenring piston ring

[fidiro]

As some of you may know I recently installed a GOLF piston in one of my Makita/Dolmar dpc 7311 concrete saws and so far so good. But I have not had it out in the field yet.

I have the other 7311 saw waiting to be taken apart to do the same repair and I am planning on possibly using the OEM scored piston and installing a new ring to see what happens. Is this going to cause more damage or is this something that if it works it works and if it doesn't I will new the new piston as well? I will clean the cylinder and hone it if necessary but the other cleaned up pretty well with just some sandpaper.

Has anyone used either Caber or Kolbenring rings? Caber is about $3 more. These are the only two I have come across so far in the 50mm x 1.5

Should I give the scored piston with new ring a shot to see what happens? What is the worst that can happen other than losing a new ring and the time to pull apart and put back together?

 

[southbound]

I used Caber in my 064 with a 066 top end..I have had no trouble out if it..

Now how bad is the piston???

Chamfer the skirt!!!!!!

 

[fidiro]

Just went to check my camera to see why those pics came out like that and it seems my 3 year old daughter thinks she's a photographer when no one is looking. Just wish she would keep the butter on the bread and not on the camera lens.

Hope these came out better.

 

[southbound]

Piston looks bad.. Have you tried to clean it up any???

 

[fidiro]

Piston looks bad.. Have you tried to clean it up any???

It is pretty scored on the exhaust side. I lightly sanded it over the scored side with 400grit. I didn't do it too long though, just enough to round over all the edges.

Should I still get a ring to try it out or just not worth the effort in the end? I don't care if I waste a ring trying, I just don't want any thing else to get damaged like the jug.

 

[pioneerguy600]

I have ran some pretty nasty pistons when I had to make a saw run until a new piston could be brought in. Yours looks like it would run just fine if all the high spots were flattened down to the original piston skirt surface. I lay a piece of machine paper flat on a sheet of glass, then lay the side of the piston damage side down on the paper and rotate the piston against the paper in such a way as to remove high spots, watch between strokes to see if material is being removed from the original surface of the piston skirt. You don`t want to remove material as that will make the piston undersized. If the ring lands are still in good condition to hold the rings and let them flex then run that piston, it should run for a good many hours, worse case is it will scuff up a little.
Pioneerguy600

 

[Roanoker494]

Has anyone used either Caber or Kolbenring rings? Caber is about $3 more. These are the only two I have come across so far in the 50mm x 1.5

I have ran several sets of Caber rings and they seem to work very well. I believe Caber is the brand of rings that Meteor pistons use, may even made by the same manufacturer. As long as the ring groove is not smashed I would polish the piston up and give it a try. Check with site sponsor http://www.cmsmallengines.net/, his handle on here is lawnmowertech37. He had mentioned having some quality aftermarket rings for cheap.

 

[fidiro]

Thanks for the tips. The ring was pinched in just a bit but enough that when I tried to pull it off it broke in half. I then ran a ring half through the channel and it looks good. The bad is the skirt but channel is definately not smashed or damaged.

I'll look over that site to see if there is a different option of rings to get but so far I still only have found a set of 2 kolbenrings for $11 shipped or just a single Caber for $8.50 shipped. I was leaning more toward getting the two kolbenrings so that I can keep a spare just in case but may just order the one Caber if I cannot find another option since there are two votes for caber.

 

[southbound]

Don't forget to chamfer the skirt!!!!!!

 

[fidiro]

I will chamfer the skirt as soon as I figure out what that means. LOL

I don't know what it means to chamfer the skirt hope someone can explain to me.

Meanwhile I will take the advice to put paper down on top of a very flat surface and roll the damaged side of piston over it some. I know the piston will not be smooth on exhaust side in the end, otherwise it will be undersized.

 

[southbound]

Ok not the top of the piston where the rings go the other end...

Take a flat file and bevel the edge the out side edge I will try to take a pic once the battery's are charged....

 

[dellwas]

I don't think Calvin is a sponser here now. He made a post the other day saying so. He is listed under sponsers, when you click on it, nothing comes up. He also posted that he was losing his internet and the only access he had was at the Public Library.

I have ran several sets of Caber rings and they seem to work very well. I believe Caber is the brand of rings that Meteor pistons use, may even made by the same manufacturer. As long as the ring groove is not smashed I would polish the piston up and give it a try. Check with site sponsor http://www.cmsmallengines.net/, his handle on here is lawnmowertech37. He had mentioned having some quality aftermarket rings for cheap.

 

[Zero Gravity]

Just went to check my camera to see why those pics came out like that and it seems my 3 year old daughter thinks she's a photographer when no one is looking. Just wish she would keep the butter on the bread and not on the camera lens.

Hope these came out better.

Toast!
ZG

 

[fidiro]

Toast!
ZG

I know it looks bad but I am just looking for what is the worst that can happen if I throw a new ring on it. I would think that if it works it works if not it was just a waste of a new ring.

Here are the pics after I ran it over 150 grit just on the exhaust side. I didn't want to get too much off so it still has a couple deep grooves down the middle.

 

[fidiro]

I have ran several sets of Caber rings and they seem to work very well. I believe Caber is the brand of rings that Meteor pistons use, may even made by the same manufacturer. As long as the ring groove is not smashed I would polish the piston up and give it a try. Check with site sponsor http://www.cmsmallengines.net/, his handle on here is lawnmowertech37. He had mentioned having some quality aftermarket rings for cheap.

Looked over that site and couldn't find a ring to fit. Is it possibly someone different that may carry rings on this site.

I am kinda leaning to the Caber now but was open to the option of a 'good quality ring for cheap' so if there is anyone on this site that carries it let me know.

Edit: Just looked over northwood parts and only found the 52mm Caber for $12 shipped.

 

[fidiro]

Thanks again everyone for the tips. I was not able to find a ring from anyone on AS so I went ahead and ordered two Caber rings for $15 shipped.

They should be here by Jan 6th and I'll install it to see what happens. I'll post the results when done. If it doesn't work out I guess it will be a reason to throw on a 54mm BB kit.

 

[fidiro]

Here's the update on this piston w/Caber ring. Saw if back together and it's running. This saw was missing a Cir-Clip that was nowhere to be found inside saw. there was no damage to jug if it did come off and vanish mysteriously, I think it was never installed from factory. I just used the two clips that came with the golf piston I installed in the other 7311 so that I can get it back together. I am going to find the oem earless ones to put on before I do any major work with the saw.

I'm just glad it runs with this setup and will be more at ease when earless clips are installed.

http://www.arboristsite.com/chainsaw/161441.htm#post2706746 this thread was used to try and figure out what could have happened to the missing clip, I guess we will never know.