Motohead

Okay, I have about 1200 miles on my rebuild from my broken crank late last year and I'm having serious oil consumption issues. New crank, new rods, new JE pistons, new Honda rings, new rod and case bearings, cases were fine and I de-glazed the cylinders before rebuilding. The bike runs like a high-compression VTR should, but I'm blowing smoke at high RPMs - no smoke at start up, so it's probably not the valve seals. I've used HP4 10W40 and now HP4 20W50; no noticeable change in consumption rate. I burned though 1/2 to 3/4 of a quart on a hard ride a couple weeks ago - roughly 110 mile loop. The CBR1K I was smoking (literally ) said he could smell the oil, but couldn't see it. Regular errand running/ commuting doesn't seem to use any oil.

Should I have used different rings? Is it possible the oil control ring is in a flutter at RPM? Are the rings just not fully seated yet? This is driving me nuts! Not sure if I should tear it down again or not, but I will this winter if it doesn't get better. Any ideas are appreciated.

killer5280

The Honda rings are the rings recommended by JE, so I don't think that's the problem. I have about 4000 miles on my JE pistons, but I haven't noticed an increase in oil consumption. To be honest, I haven't paid that much attention, but I haven't seen any smoke.
How did you break in the new rings?

Motohead

Thanks for the response. I know you said you have no visible consumption, but are you consuming any oil?

I did nothing special to break them in, just used a mineral-based oil (HP4) and rode it while constantly varying engine speed with little-to-no WOT for the first 1k miles. I am taking an educated guess at the mileage as I have 15/43 gearing, but it should be close enough. I was trying to remember this morning when/ if I filed the rings and I can't remember physically doing it. I'm no newbie to building engines, so I can't imagine me forgetting to do this, but like I said I can't recall doing it. I'm wondering now if that could be the issue.

Hawkrider

Well, not to be condescending, but how are you checking your oil? If you're checking it on its sidestand then you're overfilling it and the additional oil sloshing around at high rpm could be a cause. Also, ensure your crankcase vent tubes are properly installed on their respective ports on the head and airbox.

RK1

My quess is that the rings aren't fully seated yet. I've never rebuilt an engine, but I bought my VTR new and had fuel dilution of my engine oil until I had over 3k miles on the bike. I didn't do a UOI but could smell the gas in the oil when I changed it out. You might want to drop some oil and give it a whiff. If it was mine and running OK I'd put more miles on it and see if it clears up.

RK1

"UOI" above should read UOA= used oil analysis

Motohead

Don't you check it with the engine running?

No, I check it cold before I ride either on a swingarm stand or usually I place a 2x4 flat under the stand. I'll double-check the vent hoses - thanks!

Motohead

Good point and that's what I'm hoping (not being seated, yet). I think I will pull the filter and take a sample to the lab at work tomorrow and see what's going on. Yes, I work for an oil company, but I'll never talk shop on here.

Whatever the case, I think I'll keep leaning on it hard with lowest common denominator engine oil until Dec/Jan and see what happens.

RK1

Motohead;

Sounds good. I know there are differing opinions, but a lot of people still say use mineral oil, not syn or semi-syn, for break in. I frankly don't know.

I know I put M1 15w50 red cap in my bike at 600 mi. and still had fuel dilution 2.5k miles later. I then filled it with cheap 15w40 dino and the dilution was gone. That doesn't prove anything 'cause the rings may have fully seated at that point regardless, but there it is.

Motohead

Base oil actually has very little to do with it; it's the additive packages that can prolong or incapacitate (by glazing the walls) ring seat. You're usually safe with mineral-based for break-in, however, as they're cost-consciously formulated as opposed to performance-conscious.

killer5280

I do have a little consumption. Not as much as you're reporting (it seems like 1/2 quart over a few thousand miles), but more than with the stock pistons. I'll keep an eye on it and see just how much because, like I said, I haven't paid that much attention to it.

Ohio Hawk

Hum... you stated you de-glazed the bore... with what... ball hone or stone hone... also I'm not sure if the 996 engine has NCC bores or not but if they do you should never touch them with a hone.

Motohead

I was actually thinking I didn't do enough de-glazing as I did a pretty light job, but you may be right. I used an articulated three stone.

killer5280

It's not a treated cylinder.