Cylinder Head Oil Leak- Serious?

Hi, everyone. I just joined the forum because I'm thinking about buying an '81 KZ550A. It's a really nice bike, but the one thing I noticed was that there was a wet oil spot in about the center of the front of the engine. Looks like it's at the head/cylinder joint, but I didn't get a real close look at it. It doesn't seem like it's a big leak- probably not enough to drip, even. I am going to go back to check it out more thoroughly, when he pulls it out of storage.

The guy says the bike has always seeped a little oil there, but it runs great and he never worried about it. I don't mind a little oil leak, but I am worried about the head gasket leaking compression. If it's leaking oil, does that mean it's definitely leaking compression, too?

If it does need a head gasket, how bad a job is it? I have done major internal engine repairs on bike engines before, but don't enjoy it. (And never on a UJM, but on an ancient Norton.) Is the head removable without pulling the engine from the bike? Is this a pretty straightforward job one could do in an afternoon?

Anything else to watch out for on these bikes?

Thanks, and I hope I buy this thing so I get to spend time here!

David

Hello, David, and WELCOME to KZr!
We're glad you're here!

Regarding leak, would first suspect tach drive or maybe valve cover gasket (both relatively easy and inexpensive repairs).

It runs great -- they all say that.
Wonder how it will run when he pulls it out of storage. :lol:

Even if not running, there are many things to check, which can indicate how well or poorly the bike was maintained or attended, such as condition of chain and sprockets, tires, oil level, bent handlebars, road rash, rust inside fuel tank, whether carbs were drained before storage, how long in storage, will engine kick over (not frozen), and on and on.

A non-running condition usually lowers the value significantly.

Good Fortune!

Forgot to mention --- gonna need a factory service manual in any event to properly care for the bike.

Ask owner if he has one. If not . . . hmmmmm.

Good Fortune!

Thanks for the reply, Patton.

I spent a lot of time talking with the owner, who wasn't actively trying to sell it until he learned I was looking for such a bike. I am very comfortable he is a square dealer.

This bike is stored indoors and is covered. It is in excellent shape cosmetically and, he assures me, mechanically. He just needs to get around to putting the battery back in and de-winterizing it. He says he stored it with fuel stabilizer. I glanced at his maintenance records, and they appear meticulous.

It would be nice if it were a lesser gasket, but if it is a head gasket, how much of a job is it?

David

Head gaskets are not that bad and you will want to lap the valves and replace the valve seals while the head is off.

Welcome to the site.

If you have time to make the purchase (no other buyers) you could purchase a manual to see what you are getting into. Most seem to think that the factory manual is best, but I have never seen one. I have one by Clymer, Haynes also publishes one.

Both the valve cover and head can be removed with the engine in the bike.

If you can, check to see how rusted the fasteners on the bike are. projects increase in time when you strip or break a bolt.

Valve cover gasket change could be done in a hour or two. Requires removal of gas tank and coils (just a few screws).

Head gasket will take longer unless you are practiced at it. It means removal of above as well as carbs and exhaust system.

Good luck!

maybe tightening the nuts would eliminate the leak...

9am53 wrote:

maybe tightening the nuts would eliminate the leak...

Which nuts? Certainly not the head bolts.

David

If the head bolts (nuts) are loose then tightening them might seal up the leak.

I'm assuming that if the head bolts are loose the engine has issues that a simple "tightening" isn't going to fix. Like needing at least a new head gasket and proper re-torquing.

David

Maybe, but you never know and it's free.

db4570 wrote:

...am very comfortable he is a square dealer...stored indoors...covered...excellent shape cosmetically and, he assures me, mechanically...stored it with fuel stabilizer...maintenance records, and they appear meticulous....

All good signs!

Meanwhile, am still betting my nickel it's not the head gasket. :lol:

Before removing head, here's how I would proceed:

Clean engine really well, and when thoroughly dry, spray foot powder over edges of valve cover gasket and head gasket, and all over and around the tach drive, exhaust clamps, and half moons.

Start engine and get up close using a flashlight while the engine's running to determine exact source of the leak.

Measure valve clearances to assure they're within specs.

Perform compression test.

Perform LEAKDOWN test, which will indicate source of any compression leakage from each cylinder, intake valve, exhaust valve, piston and rings, and head gasket.

This will give a good idea of engine's overall condition.

And not only that, but also likely confirm tach drive or valve cover gasket or exhaust port as source of leak. :laugh: (Am optimistic.) :lol:

Btw, what mileage is shown on odometer?

Good Fortune!