Topic: Maui Z1 1973

[MauiK3]

I counted links on both the old and new cam chain. 61 link plates, 122 pins. In both cases.

[grcamna2]

I counted links on both the old and new cam chain. 61 link plates, 122 pins. In both cases.

Steve,is it possible the NOS cam chain tensioner could be stiff and binding ?

[MauiK3]

I’ve looked at it and it seems to move smoothly. I also counted cam chain links and measured the link length just to satisfy my curiosity. I was thinking that too much chain tension would hold the cams down too hard. I’ve looked at the oil pressure switch and the passages around it. All looks normal. It moves easily. The top cam chain idler is installed the way I marked it prior to initial disassembly but I’ve looked at photos and have seen it installed both ways. I think it’s symmetrical.
I’m going to reassemble with no valves just to spin it. I’m waiting for a gauge. I’m also going to try to make a priming setup to pre-fill the oil passages above the oil pressure switch to hopefully eliminate the time it takes to fill the head with oil.
I’m grasping here, I’m not finding anything definitive.

[grcamna2]

Steve,you Will find the problem and get this fixed. 

[MauiK3]

https://youtube.com/shorts/tWzw0jGE6pk?feature=share

Oil pump bucket test
Doesn’t prove much but it does pump!

[Terry in Australia]

The hotels near here would come get you with their Suburbans or Teslas. I'm on the the south side of the island about 1/2 mile from the ocean that is lined with hotels and condos. Just south of me starts the area called Wailea and then Makena where all the really expensive hotels are and homes of part timers like Jeff Bezos (Amazon), Peter Thiel (formerly of PayPal), Paul Simon, Steven Tyler (Aerosmith) etc. You'd be amazed at their property tax bills, more each quarter than I make in a year.

Diving back in today to look at more unlikely reasons for my problem.

Ha ha, well stuck here in icy cold Melbourne that sounds like heaven Steve, I better check my passport and see if it's still in date! Actually it's a beautiful day today, sunny and incredibly, will be 17 deg C (62.6 deg F) so a ride will definitely be in order. Gotta make hay while the sun shines, as my old grandpa used to say.

[Terry in Australia]

https://youtube.com/shorts/tWzw0jGE6pk?feature=share

Oil pump bucket test
Doesn’t prove much but it does pump!

That looks pretty good to me Steve, although, like you, I don't know how much it should be pumping. I'll be interested to see a vid of you testing everything with the valves out and the cams in.

[MauiK3]

When my gauge kit comes I'm going to set up a complete pre-prime and do the valves out spin test. I'll prime everywhere I can. If this turns out to be the answer it will leave me wondering why nowhere in any reading I've done does it mention this as a needed step.
I have trouble believing I'm the first person in the 50 years this bike has been in existence that has encountered this.
I love my CB750 by the way.

[craz1]

I have never had a problem with the Z1 pump priming with the 10 or so Z1 engines I have worked on. I also use this for assembly lube.https://www.oreillyauto.com/detail/c/sta-lube/oil--chemicals---fluids/grease---lube/engine-assembly-lubrication/624729fe33d1/sta-lube-engine-assembly-lube/stl0/sl3331?pos=3. Have you used brake cleaner with the tube to clean out those passages. Try to get that tube angled up to the drilled passage. That center idler can be mounted in any position front to back. I doubt you have a cam chain issue or idler issue. I normally(always)replace all those idlers with the Liska idlers, the center idler use a solid mount. The rubber ones get hard with heat/ age. Show us what your center idler supports look like. Should be spacers to prevent over tightening of the rubber cushions.

I started reading your posts on KZrider so I will stop posting here. I defiantly don't like to use those original idlers. They can be an issue, especially on a 50 year old engine. It's a crap shoot on weather they will fail or not.

[Terry in Australia]

Yep I think the problem is unique to your particular bike Steve, I fumbled my way through my hotrod 1100cc Z1-B build with way less care than you have, without any of the issues that you’ve had. Don’t get too wrapped around the axles about the centre idler either, there may be issues with them but the majority of Z1/KZ900/1000’s out there will still have them in place, working fine. I have a fancy APE one in my 1428 engine but only because I’m using a GPZ1100 cylinder head on it, and GPZ1100 don’t even have a central idler, so it’s needed more to take up the slack in the chain, than for anything else. I’m using the OEM central idler in my Z1-B engine with no problems at all, you can buy new rubber bases for them from numerous sellers.

As much as you love your CB750 because it hasn’t caused you the heartache that this bike has, it’s a machine and any machine can cause you grief, I’ve had at least 3 engines in my K2 Bitsa since I built it from parts in 2017, including one engine that an “Expert” built that looked great on the outside but was a nightmare inside, I had it in and out of the frame 3 times before I’d totally rebuilt it, but now it’s great. You’ll be fine.

[MauiK3]

The idler was replaced a few years ago by the PO. The rubber bases are ok and the spacers are fine. I may replace the whole thing just because.
Jeff Saunders has responded to a PM and is helping. I am grateful for his and all the help I am getting.

[craz1]

Yes Jeff knows his way around that engine. It would be interesting what he thinks about the looks of those bearings with only a few seconds of run time on them. Show him those pics of the bearings and also the cam bucket bores.

[Terry in Australia]

Jeff’s a member here, but I don’t think he’s been active here in a while.

[PeWe]

The root cause of the cam problem will be helpful  information for people wrenching with this type of engine.

Solving it without being sure about the reason will be a dwell of worries.

I have a strong feeling it will be solved and explained rather soon.

I'm looking forward to see ride pictures with that beautiful bike on roads and places with fantastic sceneries. 
Maybe at a very local food shack too

[MauiK3]

Still waiting for the gauge kit.
Since I’ve been able to see, check,blow, rinse, etc all of the path from pump to cam bearings, if I don’t get oil on a spin test I’ll have to assume it’s the pump or I have a massive short circuit oil leak which is highly unlikely due to the way the system works.
If it’s the pump, which measures fine, I’m not sure what I’ll do besides find a pump.

[MauiK3]

I wanted to check free flow to each oiling hole in the head so I put it back on and this is what I did.
https://youtube.com/shorts/idT89Lor80g?feature=share

[MauiK3]

Of course I did all the holes the same way. Seems like there are no restrictions.
Onward

[Terry in Australia]

Beautiful work Steve, it all looks spotlessly clean too, as I would have expected from you.

[MauiK3]

I tried to push some oil up into the head with my little pressurized ball jar but it did not work. I need to look for a better bottle or jar to use. Got a lot of oil on the floor, good thing I used about 2 cups at a time.

[PeWe]

This is the moment when you want to find a problem explaining the earlier issues, but easy to fix, right?

You'll hopefully find out and get it right.

[Terry in Australia]

I’ve no idea what a ball jar is Steve, I heard once that Ringo Starr kept his tonsils in a jar, but yours sounds a bit extreme? Can you just use an oil can like everyone is and try to pump it thru?

[RAFster122s]

Ball is a brand of glass food canning jars. They come in pint and quart sizes.

[Terry in Australia]

You’ve just reminded me that I have a “Ball” jar in my kitchen cupboard, a mate in Oregan sent me some home made jam (jelly) in a half pint jar.

[MauiK3]

I've done something like this before, I'll get a photo up when I have a working example. I'm trying to duplicate running pressure by feeding oil up into the cylinders and head, no cams installed, using just a few pounds of air. I now have a better lid for the jar to modify and set up a little air pressurized rig to push oil.
Canning jars come from Ball, Mason, Kerr and maybe a few other names. They have metal rings with sealing lids, good for canning and storing foods in the tropics to keep out bugs. I started with a wide mouth and metal ring, actually not well suited for pressure. I'm switching to small mouth, stiffer lid and threads. This version should work.

[grcamna2]

I've done something like this before, I'll get a photo up when I have a working example. I'm trying to duplicate running pressure by feeding oil up into the cylinders and head, no cams installed, using just a few pounds of air. I now have a better lid for the jar to modify and set up a little air pressurized rig to push oil.
Canning jars come from Ball, Mason, Kerr and maybe a few other names. They have metal rings with sealing lids, good for canning and storing foods in the tropics to keep out bugs. I started with a wide mouth and metal ring, actually not well suited for pressure. I'm switching to small mouth, stiffer lid and threads. This version should work.

I hope this works,any pics ?