Copper filings on oil filter base.

Galactica wrote:

Hard to say how many miles on the engine. The odometer read 8900 miles when I got it, but the motor is kinda tired. Compression is 115-135. I've put about 14000 km on it (about 8700 mi), and I change the oil about every 3000-5000 km ( about 2000-3000mi).

I just got back form a 600km (400mi) ride. Just waiting for it to cool down, then I'll drain the oil and have look.

She ran flawlessly until I pulled into the garage and I saw fuel pissing out of the #3 carb overflow. I quickly shut off the petcock, drained the bowls, removed the #3 bowl (damn it was hot), flicked the float a coupla times, reassembled, and voila problem solved

No need to fry your fingers like that. Just open the throttle full and let it slam shut a few times. That generaly will fix it.

larrycavan wrote:

Galactica wrote:

Hard to say how many miles on the engine. The odometer read 8900 miles when I got it, but the motor is kinda tired. Compression is 115-135. I've put about 14000 km on it (about 8700 mi), and I change the oil about every 3000-5000 km ( about 2000-3000mi).

I just got back form a 600km (400mi) ride. Just waiting for it to cool down, then I'll drain the oil and have look.

She ran flawlessly until I pulled into the garage and I saw fuel pissing out of the #3 carb overflow. I quickly shut off the petcock, drained the bowls, removed the #3 bowl (damn it was hot), flicked the float a coupla times, reassembled, and voila problem solved

No need to fry your fingers like that. Just open the throttle full and let it slam shut a few times. That generaly will fix it.

tap on the bowl with a rubber screwdriver handle a couple times!

hx35w wrote:

Unless I missed something in these post, what about the bronze bushings in the connecting rod at the wrist pin and piston?

There are no bushings in the connecting rod small end. It is steel on steel.

testarossa wrote:

nads.com wrote:

otakar wrote:

110% certain they are roller bearings on a pressed crank.

Why arent cranks made with babbit bearings and pressed together parts? The you could replace damaged journals and youd have the high rpm sometimes sought after.

nads, I think that you have to look at it as an engineered system. First, in 1975, 10,000rpm was pretty hot. Second, it's not just the main bearings are not the only limiting factor on the redline. Two valve heads can't breath very well at the top end, and still be streetable. Even if you do use huge valves to breath up top, then you have to run high valve spring pressure to control the valve float. This is hard on camshafts and timing components like cam chains etc. Mother Kaw had to make a decision about performance/durability and in the 1970's they definantely erred on the side of durability. It's the whole reason that we laud the KZ for being reliable, and still ride 30 year old bikes all over the country to this day. If you want a motor that you can rev to the moon, then go get any newer 600 cc sportbike. Most of them redline around 17,000 rpm and make more hp than your KZ, and come with a warranty. Will they last 30 yrs? Not likely.

And they don't start making any power until around 8000 :silly:

So I drained the oil last night and checked for debris on the on the filter base. Clean as a whistle and no debris on the magnetic drain plug ( never has been ). I'm not going to worry about it any more.

Will post pics of my weekend trip soon. We had an awesome campsite just off the road right next to Cayoosh Creek. It was so quiet out there except for the sound of the creek. After 8:30 PM or so we didn't hear a car until about 8:30 AM.