Fresh honed cylinder eating rings

Cleats Onionpockets /

Puch Korado cylinder, single L-ended piston ring. Got this one from overseas and gave it a fresh hone with a new set of flatstones, went medium speed with plenty of oil. It has a beautiful crosshatch, and feels smooth to the touch. I'm filing the ring gap so that it's just shy of touching when installed, and the bike will fire off just like it's supposed to. Mixing 50:1 with Motul. Within a few minutes of running at idle, it starts farting and stumbling, then refuses to hold an idle. When taken apart, the ring gap is now enormous, and all the compression is just chuffing past the ring through the gap. What gives? It seems like it's wearing down the rings super aggressively, to the point where the gap opens up. But it's the correct ring for the piston, and it starts out running perfectly. It's not snagging on a ring, no scratches visible in the ring after it's changed shape...it's almost as if it's being abraded down.

Re: Fresh honed cylinder eating rings

Was this a nikasil or cast iron cylinder?

Re: Fresh honed cylinder eating rings

Use Molybdenum rings

Re: Fresh honed cylinder eating rings

Where does the ring end gap pass through?

Re: Fresh honed cylinder eating rings

Sounds like it was too coarse of a stone.

Re: Fresh honed cylinder eating rings

I agree, but not seeing it I'm guessing that somebody is not happy with there new mate in there. Every thing all lined up? Clip's ok? That got me once. But it sounds like you're knowing your sheet.

I had a flash caromed cylinder that bit me in the ASS several times!,,,

Turned out...... it was a peice of junk Floating around in the bottom end that was just trying to get out! Very $ lesson I learned....maybe this will help.

Re: Fresh honed cylinder eating rings

So is it too honed? It's cast iron if it's honed ...right ? So hit it with some 400 grip wet dry paper. Yes?

Re: Fresh honed cylinder eating rings

if it is too honed you could go for an over bore piston.

Re: Fresh honed cylinder eating rings

Cleats Onionpockets /

Welp, turns out I need to tear down the engine anyway. While cranking it over, I noticed a wobble at the flywheel, which turned out to be a bent crankshaft on the flywheel side. C'est la vie.....

Re: Fresh honed cylinder eating rings

How do ya think the shaft bent ? Did u previously rebuild the case and if so how did u get it together ? And how have u been removing the flywheel?

Re: Fresh honed cylinder eating rings

> Cleats Onionpockets Wrote:

> -------------------------------------------------------

> Welp, turns out I need to tear down the engine anyway. While cranking it

> over, I noticed a wobble at the flywheel, which turned out to be a bent

> crankshaft on the flywheel side. C'est la vie.....

Cranks are typically 3 piece. They can be knocked out of alignment without bending. Could be as simple as re aligning a crank that's been dropped.

Re: Fresh honed cylinder eating rings

Cleats Onionpockets /

The taper shaft at the stator side has a wobble, not a rotational walk. This was a complete rebuild with new bearings, which were installed with the freezer-toaster oven heat treatment. Everything assembled smooth like butter, and it spins freely in the bearings without any kind of a hitch. Watching the shaft where it's closest to the bearing, it's dead on. But the threaded tip is wiffling off axis ever so slightly, which translates to a noticeable shimmy when the flywheel is installed. I have a threaded puller for removing the flywheel, and it was never dropped/smacked while in my posession. The threads themselves on the crankshaft are perfect too, which has me wondering how this thing got slightly bent as well. You'd think if it was dropped, it would have mushed the threads somewhat.(edited)

Re: Fresh honed cylinder eating rings

And u bought the crank new ? Too bad dude.

Re: Fresh honed cylinder eating rings

Cleats Onionpockets /

Bought new, partially assembled, and then put into storage for over a year while I was dealing with other things. Now I have it out of storage, and I've noticed this problem way past the return period. Live and learn, I guess.

Re: Fresh honed cylinder eating rings

> Cleats Onionpockets Wrote:

> -------------------------------------------------------

> Bought new, partially assembled, and then put into storage for over a

> year while I was dealing with other things. Now I have it out of

> storage, and I've noticed this problem way past the return period. Live

> and learn, I guess.

There are ways.

Buy another. When it shows up return the old defective one for replacement. When second new one shows up sell it.

Re: Fresh honed cylinder eating rings

Cleats Onionpockets /

Not a chance. Karma's a bitch, and I don't want her coming to visit.

Re: Fresh honed cylinder eating rings

Dirty30 Dillon /

> live ɘvil Wrote:

> -------------------------------------------------------

> There are ways.

>

> Buy another. When it shows up return the old defective one for

> replacement. When second new one shows up sell it.

Wow, that's a real piece of shit move

Re: Fresh honed cylinder eating rings

Nice live evil...so someone else on moped army can post about it. Or make Benji eat it because we don't know what happened.

Re: Fresh honed cylinder eating rings

> Cleats Onionpockets Wrote:

> -------------------------------------------------------

> Not a chance. Karma's a bitch, and I don't want her coming to visit.

Did ya send em a message inquiring about it? Could be that they are aware of it and had others.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account