Goodbye crank bearings

Well Wook, I completely understand what you’re saying and I do agree. It probably is not the most intelligent thing to do but it is my main source of transportation. I’ll definitely be rebuilding the old one and if the donor takes a dump then I’ll have this one to swap in. The main driving factor in my purchase of the 40yr old donor is time, I don’t currently have the time or space to rebuild one. I’ll definitely be updating this thread as I progress in the tear down and diagnosis of the current bad motor. Besides with the full donor bike I have plenty  of parts that I can salvage if needed. Carbs, coils, brake rotors, brake pads, and various other parts. 

Makes complete sense, only you know your circumstances and what meets your needs best. Fingers crossed you get lucky and the donors a peach 

I have a 750 crankshaft if needed ?

Welp, we just went to check it out and it was NOT what was described on the ad. It had been dropped, the plastics were obviously rattlecanned, it was leaking oil, handlebars were bent and the thing that made me pass was the clutch would whine when the lever was pulled in. I didn’t think it was worth it with no title and all it’s issues, even as a parts bike. I guess I’ll spend tomorrow tearing down the original motor and seeing exactly what bearings went bad. 

I plan on pulling the motor but I want to ask, can I get to the crank bearings and rod bearings without pulling the head and jugs and just splitting the bottom case off? 

Yes, you can do that if you pull the engine out of the frame.  There are two sets of bolts to remove.  One set is M6 and most of them are on the top of the engine, but six of them are on the bottom at the front.  There are also 10 M8 bolts that you can get at from the bottom.  You will also have to remove the clutch and primary shaft, which is probably best done with the engine in the frame but can be done out of the frame as well.

You can also split the cases with the engine in the frame, but you would have to remove the head and barrals.  I just did that job a month ago on a 650.

Yes. Just need to remove the oil filter and the covers (generator/timing/clutch/sprocket). I have some spare stuff so I may be able to help if things need replacing. 

Alright, sounds good then, I’ll see what I can get done this week, since I’ll be removing the clutch and stator cover. I’ll order those gaskets and and get them coming my way. Would you all recommend changing the old Phillips head screws to a stainless steel Allen head cap screw? I think that would be easier to remove than these old Phillips heads. 

one question about gaskets for you. What’s the difference between Z1 part (201-0112) and (11009-1984), other than $20.49? Is the vesrah gasket one I need to avoid?

The old screws are not Phillips.  They are JIS.  You should get some JIS screwdrivers (See Z1 Enterprises) or you will mangle the heads if you use a Phillips screwdriver on them.

Vesrah are acceptable in my opinion.

Question for you all, what part would fail if my cam chain tensioner was not working properly? Obviously it may or may not explain the metal in the oil but when removing the tensioner, it did not spring out when removed. In fact it did not move period. I had it depressed and locked in when I was doing my valve clearance job, could it have not sprung back, providing no tension, and messing something else up, other the oil pressure issue?

You may have found your knocking issue. The metal shavings may be from the chain wearing on the block. I'd pull the head to see. 
Steve

Welp, maybe… if I’m gonna do it, I’ll probably have to replace the head gasket. And possibly anything else that got damaged. 

what head gasket would you all recommend? The ones I’ve seen on Z1 are $100+

I’ll pull the head tonight but I’ve already got the motor out. 

Where would the cam chain wear if the tensioner wasn’t working? Presumably it took off quite a bit of material but I’m not sure where to look.