Piston Ring question?

The rings fit inside the bore with the top ring measuring an end gap of .43mm while the ring to land is .03mm

These measurements seem to fall within spec, should the shape be an issue?

Yes circlips are on the way from Z1E.

So ring end gap=OK?
How about ring land fit? Rings must fit correctly to the land area of the piston. If the grooves are clean, then a test fit here would be next, then test fit 1 piston with rings installed into the bore, with some engine oil. It will be a bit stiff but you should be able to slide it reasonably easily. If all fits correctly.

so the ring end gap spec in my manual is listed as standard =.3mm and wear limit = .7. I am at .4ish.

Also the ring/land spec is .06 as standard with a wear limit of .18. my measurement is tighter than spec at .03mm likely due to a bit of carbon.

piston will slide into bore with rings installed.

Sounds like other than some more groove cleaning, things will workout for you. I used to dip pistons overnight in real carb cleaner, took all the crud off. Nowadays its a brass brush and a solvent tank, and some brake clean as well. Labor intensive for sure, but get those ring grooves clean, or just like not enough end gap, you can seize a ring in the groove. Probably some of the old ones were stuck like this. Then instead of being able to reach the bore surface, you'll be getting a gap= poor seal/ blowby= powerloss.

Thanks for the help, I feel a bit more confident about going with these rings.

One more thing.... I saw you gave some advice to a guy on finding part number 92071-102 (Carb grommets) I have heard the ugly word about it being discontinued and have tried multiple vendors. I got ahold of wired george who said he had hundreds but would not sell parts only install with a carb rebuild which I have nearly completed arleady. Redline cycles has used ones that he is willing to sell, but I'd prefer not go used on this.

This is extremely frustrating, more so than the rings.:S

Wasn't me you sourced those. But there is a Vendor Link at the top here on KZR, that has a lot of places to look. Always Google the part # and do an Advanced search on Ebay with the Title and Descriptions Checked. I certainly would say George must have a supplier for new ones, maybe you can find it?
Or anybody know where?

I would not be afraid to buy a used part from Jim at Redline. Very straightforward guy in my dealings with him. And he specializes in our bikes. If he says it's good, that's good enough for me.

it may be my only option at this point. I was going to give my search for "new" grommets another 24 hrs before purchasing.

I have found a few posts by other members trying to source this part and have emails out to them as the threads were never followed up with the solution.

after cleaning grooves I did not get much diff in the ring/land gap. The spec calls for a ring of thickness 1.45mm, my new rings are running a little thicker at 1.48. Measured the old rings and they are coming in at 1.45?

That extra 3 hundredths of a mm (.03) is what I need to make spec on the ring/land gap of .06.

How critical is this?

This is for the 81 up J series engines. Notice a slightly tighter tolerance. Now if you have your ring grooves really clean, and the rings rotate quite freely around the piston land, I believe it will be OK. But make sure there is NO carbon left. Since you have the old rings, take and break one of them, then using the UN broken end put it into the groove as a carbon scrapper. Do not gouge the metal. Be careful and you will most likely see more black carbon come off.
Here is the chart from the FSM for the J's:
Hope this helps.
And no luck so far on the Shaft seals, seems to be NLA.

calvin17d wrote:

so the ring end gap spec in my manual is listed as standard =.3mm and wear limit = .7. I am at .4ish.

Also the ring/land spec is .06 as standard with a wear limit of .18. my measurement is tighter than spec at .03mm likely due to a bit of carbon.

piston will slide into bore with rings installed.

If the standard is .06 and you have a measured .03 you're already tight. If the new rings are .03 thicker than the old looks like you ended up about .06 tighter than the standard= no move-y in the groove-y.:ohmy:

the ring groves are spec'd at 1.51mm so assuming that my grooves have not worn at all ( I measured them in the vicinity of 1.5) that my clearance would be about 0.03mm before thermal expansion. My concern is whether this is sufficient clearance to account for expansion, as the rings cold do move nicely in the groove with their .03mm of clearance.