1974 Honda Z50

I think the hubs were polished, then clearcoated. The same as a CT70 of the same era/year.

CJpayne:
Thanks for the response.
I really want to keep this bike as close to original as possible, is there a way to determine if they were originally painted or polished? If they are polished, what's the best method to return them to a polished state? Is that even possible now that I've sand blasted them and potentially destroyed the finish.

Should I re-strip them? What is the best way to do that?

I assume if the hubs are polished aluminum that fork plate in my picture is as well. The entire assembly is confusing. The handlebars are chrome, they plug into a polished aluminum piece, which sits on a that plate but all the surfaces look different.

Thanks

Josh

I'm no expert on Z50's, but if they were polished, they're pretty much destroyed if someone can't polish them back. I'd score another set. I don't think they're hard to come by......yet.

The brake panels (part that holds the pads) had more of "brushed" finish. Similar to what you get get by using worn sand paper or a scotch brite pad. The hubs, I think, were 1/2 & 1/2. The brake hub portion had the same finish as the brake panels. However, I believe the sprocket side and corresponding side on the front hub was actually painted cloud silver. Could be wrong on 1/2 & 1/2 as my "pattern" may not have been an untouched item.

As CJpayne pointed out, the bare aluminum sections were in fact clear coated, and tough too. Different schools of thought exist on using clear coat over bare aluminum. Some don't because it's easier re-polish later.

76 thru 78 used painted hubs and brake panels.

You should be able to remove the paint with your paint removal of choice and polish or give them a "brushed" finish. Or check out e-bay; they're plentiful and not that expensive. It all depends on just how perfect you want to be.

My 74 was an untouched original and the hubs did have a brushed finish that were clear anodized on both sides. I opted to remove the clear and buff then re-clear. I used 600 wet to cut through the clear and then gradually went finer up to 2000 grit before buffing. Here's a link to Z hubs. Contrary to what some think, polished aluminum must be cleared or it will oxidize in no time. I don't use anything that has to be sprayed from a can or gun. I only use Everbrite and wipe it on with a cloth.

Thanks to everyone who responded.

I think I'm going to pick up a bench mounted buffer and use the wire brush and buffing wheel as recommended by Bc17A. Worst case, its doesn't work because I sand blasted them, and have to repaint. Just time, but I'd rather they are factory correct.

Does anyone know what type of wire brush that is? Are there different coarse levels like sand paper?

Thinking about this machine:
http://www.princessauto.com/en/detail/powerfist-6-in-bench-mount-buffer/A-p8502494e

randomgoood said:

Thanks to everyone who responded.

I think I'm going to pick up a bench mounted buffer and use the wire brush and buffing wheel as recommended by Bc17A. Worst case, its doesn't work because I sand blasted them, and have to repaint. Just time, but I'd rather they are factory correct.

Does anyone know what type of wire brush that is? Are there different coarse levels like sand paper?

Thinking about this machine:
http://www.princessauto.com/en/detail/powerfist-6-in-bench-mount-buffer/A-p8502494e

Click to expand...

It might take a more coarse paper (400)to start since you sand blasted them but with a bit of work you can make them look like new. Paper is available at any hardware or paint store. Silicon carbide wet/dry in the variety pack is what I use.

Thanks bc17a for the info. I just ordered some Everbrite. Looks interesting, and probably a lot better than non catalyzed clear coat.

If you use a wire wheel on the aluminum, proceed with caution. It's really easy to gall the surface, leaving a weird (and kinda fugly) appearance that's very difficult to correct. You might be better off wire brushing them by hand. What you might not yet realize is that the surface must first be uniform, i.e. any oxidation + the etching/pitting it caused, has to be sanded smooth. Otherwise, it'll never look right...unless it's going to be painted. Z50 hubs are relatively hard alloy castings yet, they tend to be deeply oxidized. I suspect that's because the OEM sand castings were anything but level & smooth. It's a p.i.t.a. for the restorer...labor-intensive and a judgment call between removing oxidation and obliterating details.

Can't recall, offhand, when they went from brushed/polished hubs and polished brake plates to silver painted. The early non-painted types were both factory clearcoated and it was very good material, though kinda thick and not quite clear. The polish quality of OEM brake plates varied, as did the candy paint jobs of the era. But, I've owned NOS examples that were surprisingly mirror-like. Same goes for triple trees & folding bar clamps.

In some instances, such as cam & points inspection covers, leaving the polished alloy raw and giving it the occasional Shiatsu makes sense. Those parts are easily accessible, highly visible and subjected to heat + abrasion. Wheel hubs & brake plates, are neither easily accessible nor subjected to much in the way of heat, or abrasion. IMHO, they should be clearcoated. 21st century materials are far less opaque, or off-color...and they can be removed with lacquer thinner & a rag, if need be, for a quick re-polishing. After 15 years, the rear brake plate on my daily rider CT70 still looked as good as it did the day it was restored - no reason why your Z50 won't hold up as well.

You have me confused, on this forum you list it as a 74, on the other forum you list it as a 79?

Totally agree on Racerx's comment about the wire brush treatment. Did one that way early on and hated it. Sanded it down and started over. A wire brush running at 3600 RPM on aluminum will leave an appearance that will etch your brain. The factory clear coat is really tough. The only readily available chemical I've seen that will remove is Aircraft Paint stripper....and even then you have to scrub a bit.

The last hub I did where I actually liked it was by using a Dico Nyalox brush (orange, I think). This is more of a "sanding brush" than a sanding wheel. But again, I'm after the brushed look, but don't use a wire brush to get there.

allenp42 said:

Thanks bc17a for the info. I just ordered some Everbrite. Looks interesting, and probably a lot better than non catalyzed clear coat.

Click to expand...

I used the original everbrite years ago and when I called to order more they told me they had a new formula for bare metals so I ordered that. The difference is the original takes overnight to dry where the new formula "protectaclear" dries fast. They both work great and keep the polished aluminum shining for years. I never bothered with their cleaner, just wiped the freshly polished parts with window cleaner then wiped on the clear.

Spizz said:

You have me confused, on this forum you list it as a 74, on the other forum you list it as a 79?

Click to expand...

You're right, I made a typo. The bike is a 1974.

allenp42 said:

Totally agree on Racerx's comment about the wire brush treatment. Did one that way early on and hated it. Sanded it down and started over. A wire brush running at 3600 RPM on aluminum will leave an appearance that will etch your brain. The factory clear coat is really tough. The only readily available chemical I've seen that will remove is Aircraft Paint stripper....and even then you have to scrub a bit.

The last hub I did where I actually liked it was by using a Dico Nyalox brush (orange, I think). This is more of a "sanding brush" than a sanding wheel. But again, I'm after the brushed look, but don't use a wire brush to get there.

Click to expand...

Here is a link with picture from a guy who used a wire brush to remove the factory coating, followed by a polish. Definitely a lot more polished looking then brushed looking.
http://www.cttrailbikes.com/Z50Hubs.html

The ignition cover on my bike was cracked so I removed it yesterday to have a look inside and clean up the front sprocket. I've ordered a new cover that should arrive next week.
I noticed after removing the cover there was an additional threaded hole (see picture below with red outline). What is this for? There was nothing threaded inside.

I also noticed the front sprocket had some play in it. Not a lot but some. How much is normal?



Note: This is a stock photo from the internet, not my actual bike.

Notice that hole, covered with a ragged plug, above the countershaft? K1 & later have a neutral light switch assembly there, instead. It's held in place with a stamped steel retainer; the mounting screw uses that hole.

A fair amount of sprocket wobble is not only normal, it's part of the design. As long as the splines are not visibly worn, which they rarely are, no worries.

Thanks for the background on that thread hole racerx, much appreciated.

As for the front sprocket, I wasn't sure. At first I thought the entire shaft was wiggling but after a closer inspection it was just the sprocket. I thought perhaps it was lose due to wear, but its not overly lose so it must be as you say, part of the design. Thanks.

Little bit of good and bad the past couple of days.

I was in the final steps of prepping the gas tank to be painted when I noticed a number of pin holes in the bottom. Not happy! The metal does not appear to be super soft so I briefly considered my options of replacing the tank with an aftermarket, but after some research I've decided to try and use an interior epoxy coating called POR-15. Ordered it today, it will be in tomorrow, so we'll give it a whirl and see what happens.



I also decided to polish the hubs. Played around with one piece for about 10 minutes alternating between 150 and 400 grit sand paper followed by a quick power buff and the results were encouraging. Here's a picture of the silver painted hub and the one I began polishing.



Best news of the day, a package arrive for me with a few parts that I'd ordered. Still waiting for a bunch more that I'm expecting next week, but the shipment definitely improved my mood and got me re-energized. I can feel the bike coming together. Thanks to Keith at Phatmx!

I'm digging the rear shocks with black springs! Not OEM but I still have the originals if I ever want to return to stock Honda.



Once I get the gas tank repaired, I'm going to send the frame and parts out to be painted. That should give me some time to finish polishing up the hubs and other aluminium components.

Two other questions:

1. What does everyone do with their existing nuts, bolts & axles. I'm going to replace a few as they're damaged beyond repair but is there a way to refurbish others? I've heard you can place them in vinegar to help clean them up a bit, but should I be painting them or at least clearing them?

2. I haven't touched the engine, outside of cleaning the exterior. I noticed the carb was missing the air filter, so I've replaced it. Is there anything mechanical engine wise I should look into since I have the engine out of the frame? Are there regular issues these bikes encounter that require maintenance that I should check into. The bike was running fine prior to being disassembled but I thought I should check. While cleaning it I noticed its missing a few screws/bolts in various places. There is also a mismatch of hardware, which leads me to believe someone else has been in it at some point. Not sure if that's a concern or not.

Thanks again for all the advice. Will update when I have more news.

I'm going to take pictures of the front and rear sprocket tomorrow and post them, they're a little warn, and I'd like to know if they should be replaced.

Final note: Baby still has not arrived, but could be tonight! If so that could change the schedule a little but I'm hoping to still find time to work on it.

The bike is a 1974 ,that's like 42 years old at this point ,I would be more concerned if somebody had not been in the engine than if somebody had at this point .I would at minimum clean the spinner ,adjust the valves ,and install new points and condenser if it was mine .

Hi Randomgood,

First of all, I would removed the small nylon tank filter/screen that is still stuck in the nipple on your tank. Gently try needle nose pliers or maybe a small screw driver to pry it. Even if you have to push it back into the tank, get it out. If you use POR or other sealers, you may end up with a plugged port -

Nuts and bolts: Clean them up and use them as is, or polish and re-zinc....or buy new. I have done all 3 depending on what look I after.

Engine: Have you heard it run yet? Regardless, without a doubt, remove the right side clutch cover so you can get to the clutch. Pay attention to how the levers, springs, oil pass thru tubes come apart. You'll want to remove the cover on the clutch and clean out the sludge that will be inside. That's easier said than done because sometimes the clutch cover screws can be a real pain to remove.

I'm attaching a couple of pages from the parts manual showing the clutch cover and what's behind the clutch cover. I hope you have an impact screwdriver; if not, order one now.

The screws that are a pain to remove is item number 26. Some recommend to change these out a flat head allen screw to avoid the headache the next time around. Also, oder new gaskets as well.