Fixing Up My Father's '73 Z1

I flew out of town near Chicago this last week for work, so didn't get a chance to do much this last week.

However I did find a nice original Kerker 30 minutes from where I was working. It's the 70's style with the small badge (missing the badge though). Had a nice chat with Miki at Miki's Motorcycle repair.

I originally planned to split it and ship it home, but wasn't able to split the get the meg off with all of the old exhaust sealant and no tools! I ended up just switching my flight up and driving the rental car back to MI, since shipping would have been $200+ at UPS or Fedex due to the size! Worked out to be about the same price as my flight would have, and got home 1 hour earlier

Kerker stuffed in the rental car:

When I got home, everything finally came in to swap back over to the original spoke wheels ('74 & '75 date codes), so I ended up ordering a set of tires this weekend. Still need a rear sprocket, but I have a few laying around. Will need to see if any will work close to the stock 35t gearing to bridge the gap until I get a whole new set.

In the mean time, I decided to pull the valve cover & check the clearances. Turns out almost all were way too tight, so I have some new shims on the way from Z1E.

While waiting for shims, I decided it would be a good time to strip the valve cover and get ready to repaint. The old paint was pretty rough, looks like it had about 3 layers built up over the years.

Valve Cover with some paint stripper:


The motor also needs a good coat of paint, so it will be getting a similar treatment to the valve cover. I always just unbolt the cams instead of messing with a shim tool.


Front of the engine is filthy due to the tach seal leak. Next steps will be to plug up the exhaust ports and get to cleanin'

gvsu141 wrote: Ended up using the crazy glue method, seems to be holding so far.

Can you point me to the "Super glue method"? I might have to tackle this soon. Thanks,

OP - Looking good. I subbed to the thread to steal some ideas.

Conspiracy wrote:

gvsu141 wrote: Ended up using the crazy glue method, seems to be holding so far.

Can you point me to the "Super glue method"? I might have to tackle this soon. Thanks,

OP - Looking good. I subbed to the thread to steal some ideas.

Thanks!

The "Super glue method" involves sealing the fabric like insulation on the wires with super glue. This insulation acts like a candle wick, but for oil causing leaks. I cleaned the insulation very good with brake cleaner, then put a little super glue on the wires once dry. The insulation wicks up the glue, blocking it so no more oil can seep through. I then coated the wires and plug with RTV like normal and bolted it back up. This allows you to reuse your existing grommet if it is still decent without having to cut or soldier any wires.

killer project!

can't wait to see how it evolves.

keep us posted,
leon

Well, after a valve adjustment, I found cylinder #2 to still be low on compression - around 95psi. Other cylinders are in the 125psi - 135psi range. After doing a leak-down test, looks like I have at minimum issues with the intake valve on cylinder #2. Cylinder 1 tested great, right around 10% at 100psi. I didn't get a chance to leak-down test 3 or 4 before starting to tear it down, but they had good compression as well, so it makes me think the top end is in decent shape.

I'll check the cylinders when I have the head off also, and debate on new rings while i'm in there. Doesn't seem to be carbon or anything causing an issue. Looks like I'll pull the head while I'm this far and check it out while I do a valve job & new APE seals.

Question for the guys that went with oversize valves - Is it worth it over stock valves? I see APE makes the 37.5mm intake valve that is .055" short. Is this all that's needed if I went with the next size up for intake & exhaust (37.5 & 31)? The bike will have a Kerker w/K&N and stock airbox.

Some of the other guru's can probably answer this better (esp. Larry C.) but unless the head is being heavily ported with some really good aftermarket cams, there is no need for OS valves. I have an early Z1 head that has OS intake valves but it's been ported and I'm going to run some Web Cams #108 (or 109 can't remember) but it's going on the 1428 engine I've been waiting to build.

Later, Doug

No eBay APP ID and/or Cert ID defined in Kunena configuration

StreetfighterKz wrote: unless the head is being heavily ported with some really good aftermarket cams, there is no need for OS valves.
Later, Doug

Thanks, that's what i was wondering.

Once I finish getting it apart to verify, I'll probably just end up getting the standard ones from Z1E or Johnnys here:

Popped the valves off last night, and couldn't find anything extremely obvious on cylinder 2 that would cause a compression loss. There was a decent amount of carbon built up, but the valve seats looked OK. Seals on 1 & 2 are bad for sure.

The valve guides on the intake side seemed pretty good, but there was a little more play with the exhaust valve guides. What's the impact if I don't replace the guides right now? I'm not opposed to tackling this myself if needed, would just need to buy a driver.

On a side note, the spark plug threads on #2 are a little buggered up, so there's more resistance pulling the plug. However it still goes in and torques OK.

Cylinder looks OK at a glance (once again more carbon), No major scoring or gouges from what I can tell. If I shine a flashlight on it, I can see some vertical marks, but doesn't seem too bad, though I'm no expert. Nothing that I could even catch a finger nail on, felt completely smooth. (Last Picture)

While waiting on some parts for the head, I decided to take a break from the engine.

I pulled the set of Z1 forks from the dragbike and got to polishing. After about 3 hours total with a rag and some white diamond polish, they shined up pretty well!

Before & After: (Left vs Right side)

Next was to fit some new rubber to an original Z1 front wheel. Included a brand new tube & some Dyna beads. It was ready to mount up after installing some new dust covers on the forks.

I was also able to rob the Z1 front rotor & caliper from the dragbike. I cleaned the surface rust on the rotor with a wire wheel and touched up the paint nicks. I still need to order the correct amber reflectors for the front.