KZ1000 burning oil all the sudden

Well, I've put about 3,500 miles on my 1977 KZ1000, done all of the basic maintenance to it, stuck a lot of money into it so far. It has been running good overall, and hasn't let me down yet. Now I have a big problem. At first, it was not consuming any oil that I noticed. Then a riding friend mentioned that there was a brief plume of white smoke when I cracked her open to spank his Harley. Big deal, I thought. I changed the oil at 1500 miles twice, and the oil level was fine. Well it seems like out of nowhere, it got bad. The most noticeable is when you get on the throttle aggresively, and when you downshift/stop quickly. The other day I had to stop quick at a light, and literally had a cloud of smoke catch up with me when I stopped, followed by a brief plume of white smoke as it idled. You can actually smell the oil in the smoke too. I'm just guessing that it went through at least a quart in 500-750 miles. It is fine at low RPM's, idling, etc. and it still runs great and pulls very strong. I've noticed no loss of power. I'm awaiting a friend who has a good compression tester, but in the meantime, I'm freaking out. What are the chances of a 25,000 mile motor needing a bottom end rebuild? Is there any chance of wear in the top end making it this oil hungry?

madmatt1 wrote:

Then a riding friend mentioned that there was a brief plume of white smoke when I cracked her open to spank his Harley.

The most noticeable is when you get on the throttle aggresively, and when you downshift/stop quickly. The other day I had to stop quick at a light, and literally had a cloud of smoke catch up with me when I stopped,

With those symptoms, I would guess rings. Maybe an oil ring stuck or collapsed?

Is the compression good?

My guess is a failed valve stem seal or a faulty oil control ring.

yup, what he said...

run a compression check, that will give you the best indication of what is going on.
you prob have oil on one or more plugs so a good look at them will also clue you in.

dont recall you sayin how many miles are on the bike and if any engine work had been done to it before

I'm just waiting for my friend to get a chance to bring his fancy leakdown tester over to my house. I've pulled the plugs, none of them are wet, but they are sooty, as the bike has been running rich. By the way, it has 25,000 miles, and I have no clue if it has ever been rebuilt. My best guess would be no, it hasn't. I know this is just part of having a motorcycle, but I am pretty much beyond frustrated at this point. I love these bikes and always have, but owning this one has been a love/hate relationship if you know what I mean. I just don't know whether or not I want to spend more money to rebuild it, or just throw in the cards and buy something else.

madmatt1 wrote:

I'm just waiting for my friend to get a chance to bring his fancy leakdown tester over to my house. I've pulled the plugs, none of them are wet, but they are sooty, as the bike has been running rich. By the way, it has 25,000 miles, and I have no clue if it has ever been rebuilt. My best guess would be no, it hasn't. I know this is just part of having a motorcycle, but I am pretty much beyond frustrated at this point. I love these bikes and always have, but owning this one has been a love/hate relationship if you know what I mean. I just don't know whether or not I want to spend more money to rebuild it, or just throw in the cards and buy something else.

Throwing in "the carbs" :laugh: , and buying something else will be a whole lotta change for a "most likely", fairly easy to fix problem that wont really cost that much. + You'll just be getting another bike, in other words - another bag of headaches.

Leakdown/compression tester will not show any difference if it is just an oil control ring... sometimes is best to just use a bright light and look through the plug hole/intake/exhaust for damage/wear, or tear it right down.

Takes me about 3-4 hrs to casually rebuild the top end on a KZ, you should be able to do everything as a newb in a weekend (tools permitting). If your a newb... :silly:

GL!



PS! There's lots of short cuts to save $ without cutting quality. Keep askin, we'll let you know

If the bike set uo awhile before u rescued it and put it back on the road,chances are the valve seals are dried out and have started leaking.Those are a relatively minor and not very expensive fix.bj

I would imagine that I could handle rebuilding the top end, but the 3-4 hours you mentioned is what I'd spend drinking PBR and staring at the project ahead of me :laugh:
I'm pretty comfortable doing just about anything ASIDE from rebuilding an engine. Haven't been down that road yet. I've read that if you check the compression and have cylinder(s) that's low, and then you pour a teaspoon of oil in it and turn it over again and get higher compression, it's the rings. Does this usually work well? I just want to get the best idea of what's going on before I tear into it. I'll be honest, I'm not mentally prepared to dig into the bottom end yet...

after thinking about this for a while, something you might wanna cjeck is the crank case vent, if for somereason it has got plugged up, then it would cause high back pressure, more so under hard riding.
too much pressure can cause it to smoke.

I thought about that too, but I didn't check it because I ruled that I NEVER get lucky enough in order for it to be something so simple. Just ask my....yeah, nevermind. :laugh: But seriously, I will check that- thanks.

Yes, if compression is particularily low on a cylinder(s), then puor in a couple teaspoons oil and try again. If compression rises faster and achieves similar compression as good cylinders, then it is ring/bore/piston issues. If the oil makes no difference at all or very little (under 5 psi difference), then the problem is most likely an improperly seating valve.

Good Luck.