Meteor 066 cylinder kit - diagnose this scoring please

[Definitive Dave]

he didn't mention honing at all to me or the customer, just spinning the piston to see if it was too tight to use
if an unlabeled Hone hit me in the head I would wonder what hit me in the head
DDave

 

[pioneerguy600]

Looks like either a rough bevel on that part of the exhaust......or an out of round jug. I've seen both in AM jugs.

I had one brought in that was out of round but it scored the piston top to bottom. This piston is only scored in the area that passes over the exhaust port upper edge, the skirt below that travel area is hardly touched. just my 2 cents.

 

[hotshot]

I had one brought in that was out of round but it scored the piston top to bottom. This piston is only scored in the area that passes over the exhaust port upper edge, the skirt below that travel area is hardly touched. just my 2 cents.

Did you ever have a new one that would turn free (normal) but then suddenly feels like it's trying to bind or seize?

Then it goes free again like nothing had happened? Simply turning the FW by hand, no drill or pull cord.

 

[Mastermind]

Good eye Jerry........

 

[pioneerguy600]

Did you ever have a new one that would turn free (normal) but then suddenly feels like it's trying to bind or seize?

Then it goes free again like nothing had happened? Simply turning the FW by hand, no drill or pull cord.

I had one that would catch every now and then when turned by hand, took the cylinder off and couldn`t see anything wrong, put it back on and again there was a catch. Again take it off and when running my finger around the beveling on the ports I found a spec of plating the size of a fine grain of sand in the lower edge of the exhaust port, the piston was just passing it without getting scratched but the ring was snagging it on the downstroke only, ground it off and polished it a bit, that fixed er. On the out of round cylinder the piston would need a smack from a hammer to put it in, how the heck they assembled and run that saw without feeling that tightness is beyond me. Then again I have witnessed an assembly where the rings got broke during assembly when the cyllinder was actually hammered on to get the piston and rings in. Also seen a crank broke in two by hammering on the flywheel end trying to pop the flywheel...LOL

 

[Moparmyway]

Them scratches go beyond the port and into no mans land, look at the stepped scuffs in the cylinder. With those witness marks, that thing just looks out of round .............. I am betting on the bore gauge showing some info that will be interesting.

I aint got the experience of Randy or Jerry, but i do have enough to know that I would check that bore first !!

 

[angelo c]

I had one that would catch every now and then when turned by hand, took the cylinder off and couldn`t see anything wrong, put it back on and again there was a catch. Again take it off and when running my finger around the beveling on the ports I found a spec of plating the size of a fine grain of sand in the lower edge of the exhaust port, the piston was just passing it without getting scratched but the ring was snagging it on the downstroke only, ground it off and polished it a bit, that fixed er. On the out of round cylinder the piston would need a smack from a hammer to put it in, how the heck they assembled and run that saw without feeling that tightness is beyond me. Then again I have witnessed an assembly where the rings got broke during assembly when the cyllinder was actually hammered on to get the piston and rings in. Also seen a crank broke in two by hammering on the flywheel end trying to pop the flywheel...LOL

just another reason to "confirm" the squish measurements...forced you so spin by hand....
(and a quick compression check too)

(doesn't force you to "refuse" to accept scrunching and grinding or sudden stoppage as acceptable though... )

 

[LegDeLimber]

Do the locations of those bands of tranfer and then the light/drak areas of the plating happen to jive with your mesurments?

My money says yes.
Bore gauge might have to be walked around to get things across the the high & low regions.
You can also have a bore that's spiraled or stepped.
thus you can measuer a .015 wide band region and get the diam you need but **** aint gonna slide right.
think like a slinky laying on a hump, (aproxamatly)same size hole all th way from end to end, but take a long view and youll see that with something with slight clearnce, but 2" long, wont go past the bump.

 

[hotshot]

I had one that would catch every now and then when turned by hand, took the cylinder off and couldn`t see anything wrong, put it back on and again there was a catch. Again take it off and when running my finger around the beveling on the ports I found a spec of plating the size of a fine grain of sand in the lower edge of the exhaust port, the piston was just passing it without getting scratched but the ring was snagging it on the downstroke only, ground it off and polished it a bit, that fixed er. On the out of round cylinder the piston would need a smack from a hammer to put it in, how the heck they assembled and run that saw without feeling that tightness is beyond me. Then again I have witnessed an assembly where the rings got broke during assembly when the cyllinder was actually hammered on to get the piston and rings in. Also seen a crank broke in two by hammering on the flywheel end trying to pop the flywheel...LOL

Rough customers on breaking all those parts, then they want you to fix it, huh?

I've had a few over the years that have got new rings, proper port chamfering & measure out good, but still feel tight or "catchy". Scratch your head a while, after you pull the jug off half a dozen times to recheck everything and find nothing...

Sure makes you pucker up when you first fire them up & dial them in, but all are still cutting fine.

 

[pioneerguy600]

Rough customers on breaking all those parts, then they want you to fix it, huh?

I've had a few over the years that have got new rings, proper port chamfering & measure out good, but still feel tight or "catchy". Scratch your head a while, after you pull the jug off half a dozen times to recheck everything and find nothing...

Sure makes you pucker up when you first fire them up & dial them in, but all are still cutting fine.

Well at least you check them out but most don`t and just hope everything fits as it should. When I hear of someone getting a new P&C set I ask them what the ring gap measured, they stare at me like WTH, is that!?

 

[jonsered raket]

Least she held together!

 

[LegDeLimber]

Dang. Looks like ya had a new "will it blend?" episode, in there.

 

[Moparmyway]

added to cart!!
thanks

Any update Dave ?

 

[Definitive Dave]

I forgot to post back but I did get my gauges and mic'd this puppy.

the problem is that one gauge has 54mm as the largest size and another has 54mm as the smallest size so with either one it is not easy to get a good measurement as the gauge is either totally open or closed.
But the long and short is that the bore is not a uniform measurement all the way around, even with the measurement difficulties it is clearly not perfectly round. I did the same measurement on the other 6 cylinders of this brand I had on hand and they varied much, much less, in fact the NWP and Farmertec cylinders all varied less than the problem Meteor cylinder. The crazy thing is the piston does feel indeed a little tight going into the bore even without rings but will spin easily without scratching the piston (probably I don't produce enough rotations to cause visible indications).

Meteor sent me a replacement for the one I sent the customer so it's all good.

I did ask the Meteor/Caber sales guy about the whole process and they manufacture their pistons, rings and circlip from base material to finished product and do final manufacturing and Nikasil plating on their cylinders.

If anybody wants the out of round cylinder and piston to play with/measure let me know .
thanks to all you guys for helping me figure this out
Dave