Topic: Rebuilt Top-end Burning Huge Amounts of Oil

[mgilvary]

These rings did not have a mark on top, nor an obvious bevel that would indicate which way was up.

[HondaMan]

hm, i ran 1 piece rings in my k4 and had around 10k miles on them with bery very little oil use as in less than 1/4th a quart between oil changes they were supposedly oem rings and pistons but i dont know for sure

In situations where you are just re-ringing an engine, and are using one-piece oil rings, you must thoroughly hone the bores to make the process successful long-term. Otherwise, use the 3-piece rings. They are more forgiving of the marginal hone job. It seems that too often, the non-experienced home mechanic just does not know for sure what the honing job should look like, so it ends up not being quite enough. 

The 3-piece rings are a pain to install, though, IMO.

Really Mark.   I have always found them to be the easy part because they are low tension.

They are lower tension: I have snagged them on the bevel at the bottom of the cylinder bores more than once, which bends them and ruins them (and sometimes the bore!  ). This usually happens (to me) after a bore job, when that edge is too sharp, and I forgot to hone it off before assembly. I'm not saying it's the rings' fault... ...just that I don't like them. 

[HondaMan]

These rings did not have a mark on top, nor an obvious bevel that would indicate which way was up.

Would these pictures maybe help? They are 750 rings...

[mgilvary]

The rings looked pretty similar, if I recall. But they definitely didn't have any markings on them. I was careful to look because the Clymer mentions that.

Since it looks like I've got no choice but to pull this engine apart again (whee!), does anyone know a source where I can find rings for these oversized pistons?

Also, will I be able to reuse the overbore kit head gasket that I just put on there? If not, where do I find a gasket for these oversized cylinders?

[NickC]

Man, I hope I dont have the same problems. I recently got some replacement rings (honda) on one piston for my 550. I  don't think there is a difference between the two upper rings on the 550 though. Doesn't say anything about it in the manual or the Clymer. The oil ring gaps may be lined up? oil ring spacer overlapping?

[HondaMan]

The rings looked pretty similar, if I recall. But they definitely didn't have any markings on them. I was careful to look because the Clymer mentions that.

Since it looks like I've got no choice but to pull this engine apart again (whee!), does anyone know a source where I can find rings for these oversized pistons?

Also, will I be able to reuse the overbore kit head gasket that I just put on there? If not, where do I find a gasket for these oversized cylinders?

Since you don't have lots of miles on that head gasket, it can be re-used. You might want to get some Aviation Permatex, though, to paint around the oil passages so they get a good seal. This is a liquid form of Permatex, and never sets hard, so later disassembly isn't tough. Alternately, use FelCoBond (looks a lot like rubber cement) sealant, similar but comes in tubes and is a bit thicker. It won't last quite as long, though. I get my Permatex at Checker and the FelCo stuff at Champion or NAPA.

When you go to reuse the gasket: as you settle the head down, try to see if it has any lateral movement. If it does, try to "nestle" it into the lowest point on the used gasket. Usually, the dowel pins on Honda engines obviate this practice, but just in case...then, when torquing, go in 4 steps, saving the last 10 in-lbs for the final step. Then, when done, go back to nut #1 and back it off 1/4 turn, then retorque to final. This technique will get the last little bit of seal from the metal rings around the bores.

[mgilvary]

Excellent. Thank you.

[mgilvary]

Update:

I finally got some time to pull this engine apart again and am ashamed to report the following. It appears that I am ready for reading glasses, because, despite what I originally said, the piston rings do in fact bear a manufacturer's mark, and I did in fact install the rings upside-down (or at least most of them).

So, twenty lashes for that.

But, before I reassemble this thing and give it another try, it occurs to me that I am now not so certain of the order of the rings. Remember -- they're from an aftermarket overbore kit, and they don't exactly match the stock rings.

Here's a quick sketch of the profiles of the two top rings, and how I think they should go in. Does this look right?

[Bodi]

The guide O-rings are not your problem. It's not unusual to leave them out, the bore-to-guide clearance is a tight press fit... no way much or any oil will get through there.
I would check that the rings are installed the right way up.

[mgilvary]

Yeah, the others have already convinced me of that. My issue now is trying to figure out if I'm installing the rings in the right order. Does the above illustration look right?

[MRieck]

Yes

[mgilvary]

From the voice of authority himself. Thank you.

[Frostyboy]

I've been following this thread for a lil while & just wanted to say I'm pleased you found the answer. The other thing that pleases me is the way everyone is so happy to help & the knowledge base here is awesome. A constant stream of experience.
I hope you aren't panicky when this thing fires up again, I reckon it might take a while to burn out the oil residue in the exhaust system.

[mgilvary]

Yes, the knowledge and help here is priceless - including yours:

I hope you aren't panicky when this thing fires up again, I reckon it might take a while to burn out the oil residue in the exhaust system.

Good call. But I'll be panicky anyway. I get so little time to work on this bike, if I have to pull the head again, I'll be lucky to get it back together by summer.