Got it! 1976 KZ900 Ltd

Well, things have been a little slow working on the 900. Family and Work keep getting in the way. I also used some motorcyle money to replace the seatcover on the 750 so I'd feel good about riding it.

Anyways, since the compression test didn't do well, I took Patton's advice and tried to do a leak down test. The carbs and mufflers are off it made it easier.

Not sure if I had a big enough compressor, I borrowed a little one from my neighbor that has a little 2 gallon tank. First I used the kick start to rotate the engine 4-5 times and try and get some oil on the rings. Then I aligned the "T" on the 1-4 and checked #4 and #1.

#4 - Couldn't even build up pressure. Lots of air through both the exhaust and the intake valves, none through the rings (although with no pressure that's not a surprise).

#1 - Got the pressure up to around 30 psi. No air through the intake or exhaust, but you could tell alot was getting past the rings from the air coming out of the crank case vent.

Rotate to the 2-3 "T"

#2 - Got it up to around 25 psi. Lots of air past the exhaust valve and the rings

#3 - Again about 25 psi. but lots of air past the intake

I'm not seeing anything that's consistant as far as doing the test wrong or that I might have jumped a link with the cam chain. I'm guessing that I'm looking at both a valve job and at least new rings.

It'll have to wait until I get the back end put back together after I paint the swingarm, replace bearings and swingarm bushings. Thats all for now...no good pics, just lots of pieces and a motor on a frame.

Been a while since I updated. Got the head and the juggs pulled on the engine. About what I expected, the inlet valve for the #4 cylinder was oily. The cylinders look ok, I'll have to take some measurements to see what size rings I need to order. I'm taking them to a machinest tomorrow to get a quote for the valve job and honing.



Bad news was the cam chain guides are trashed so it looks like it'll be another month before the bike gets on the road.

Keep us posted... I'm gonna follow this thread closely, as I have recently picked up the same bike - mine needs work, but at least it's running.

Will do. Just got done talking to the machinest. Says he'll take the head apart, clean things up, measure everything, then give me a call. Got to hear lots of stories about the Z1's he's working on over the years.

Delighted to here your going to bring it back to original. Possibly the best looking LTD ever. That coming from the owner of a 79 LTD. Take your time, it'll be well worth the wait.

Good Luck and keep us posted!

Well the verdict is back and my #4 exhaust valve was bent and #1 and #2 exhaust guides were sticking. Just sent in my order to Z1 for those plus the full gasket set. Want to get the parts to rebuild the head so the machinist isn't waiting around for me. He said the cylinders were in great shape and just did a light hone on them. New standard size rings for me!

While I'm waiting for the parts, I've got some more cleaning to do on the head. I have a brass brush and some brass bore brushes that are doing a good job on the outside, but I'm a little leery of using them on the combustion chamber. Has anyone had problems with the blue scotbrite pads and carb cleaner?

Has anyone had problems with the blue scotbrite pads and carb cleaner?

Scotchbrite pads won't hurt anything, the blue are the finer (compared to the green?) ones right? The green should work too...

Good luck!

Tony

Short update - head and jugs are back and ready to go. Still need one more shim (245) and I'll be done bench shimming the head. This weekend I order the rings and cam guides so I should be ready to start putting the engine back together this week.

While I was waiting for parts, I started another sub-project, leaking stator cover grommet. I pulled the cover without any damage (love the manual impact wrench!) and pulled the stator.





I know I have to cut the wires and strip the cloth covers, replacing them with heat shrink. Does anyone have any suggestions where to do the splice?

Also, after I started cleaning up, I spotted this spring under where I was working. Can anyone identify it?



Thanks for the help!

Not sure, looks like the rear brake light switch spring on my A4. I don't know if the same switch mechanism is used on rear disc systems.

I checked that and mine break light switch spring is there, plus this one is only about an inch long. Didn't know if it had anything to do with the clutch return (Hope not).

I hate mystery pieces!

Is it maybe the carb return spring?

Progress is slow, slow, slow. We've had a couple of foster kids come through in the last couple of months. They are the youngest we've had, 13-15 months and they're pretty cute, but there's not any spare time with them. With some of the older ones we've had, I could say, "Hey, Isaac and I are going to work on the bike!", and we might get some actual work done. No such luck with toddlers, although I took the girl to bike night last month (in a car)and she liked going around and petting all the bikes! (had to teach her about hot exhausts;) )

Anyways I was able to sneak out and cobble together a carb holder I'm going to use to check the float before the carbs go on the bike.



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