1973 Z1 Maui

Looking good, those old continental pattern tires take me straight back to the 70's...!!!

Thank you
Can anyone give me an idea of how the bowl vents are routed? I imagine they go up but to where, along the upper frame tube? I know later Z1's go back over the air box or something.

Do you mean the bowl overflow tubes?  The hoses go thru that rubber thingy you asked about and drop down beside the swingarm.  The two carb vents go upwards and should tuck under the brace that is just in front of your air intake.

Upper vents is what I was not sure about, thank you

Upper vents is what I was not sure about, thank you

The carb vent tubes go up through frame tubes, flush or a smidge past the tubes.
 

Tried to do a test run yesterday and discovered I've done something incorrectly on the starter. The rubber damper doesn't stay in place. I'll have a look between Christmas things.

By the way, Merry Christmas, Melekalikimaka, and Happy Holidays to all.

As far as I know there's no rubber damper on the starter.  What are you referring to?

Sorry for the poor description. I thought the rubber damper behind the starter clutch gear was giving trouble but I looked and it’s ok. This all happened late yesterday and I’ve learned that if it’s late and I run into an issue, quit and come back the next day with more rested eyes!
I think I’m chasing perhaps two issues. I think the 2-3 points were not working right, so I’m changing the points sets and the condensers.
The other issue may be the starter motor. It checked out ok with an ohm meter when I cleaned it up but it seems to be struggling some.
Im going to do a quick compression test, the previous machine work from 2009 says “resurface head and cylinder block”. I’m wondering what the compression ratio is now. 

OK, now I understand.  And yes, I do the same thing when fatigued.  It gives some time to think things through.  Some of my best thinking occurs while asleep!

I've replaced points on all of my bikes with Dyna systems.  I'm very happy with them.  My KZ1000 (1980) also has the Wired George relay to provide full voltage to the coils instead of running it through the starter switch.

Did you pull the starter apart to check the brushes?  They generally last forever.  The ones in my Z1B are original as far as I know and are only worn half way.

Compression test would done cold, so would not give you as accurate an estimate as a warm test but would probably provide useful information.  Standard compression is 8.5/1 with no more than one atmosphere difference between any two cylinders.

So I know now I have a problem. The motor tries to start with the starter, actually sounds great, runs for a second then stalls. Then it's hard to turn over with the starter or by hand. A little careful turning with the 17mm nut by the points and it loosens up. I must have made a mistake somewhere and something is binding up. I took the pan off to check up inside and so far have not found anything. I'm going to check the timing again. I'll also look at the clutch. There is some mistake somewhere that I need to find.

If you remove the spark plugs and turn the engine over using a wrench or rachet, how does it feel?  Is it relatively smooth in rotation, or do you feel any binding?  It is really difficult to tell by a verbal description what might be happening.  Others will certainly chime in, but my first thought is to make sure valve timing is spot on and hasn't changed.  Actually, there are several "possibles" that could be at fault here, but you have to sort thru each one.  Did the engine actually run for a bit and then quit or are you referring to the sound of the starter motor itself?

Rick H.

If it actually ran, even for a second or two I would be thinking either ignition related or carburetor related.  Ignition is easier to check so I would check that first, starting with voltage to coils and coil impedance, both primary and secondary.  Also check timing.  You may be off a link.