Wednesday, October 17, 2018

Yamaha 175 CT3 Enduro - Tire Choices

Above: The original Yokohama "Trail Sport" on my bike.

I just ordered new tires for my 1975 175 CT3. I looked at a bunch of options so I thought I'd share that info here.
I should note that I only looked at dual sport tires or tires that looked similar. There are certainly more options if you want a "street only" tire.
The original rims are 1.60-18 front and rear on my bike. (The parts manual indicates that some bikes may have had a 1.85 rear rim.) The original tires are Front: 3.25-18 and Rear: 3.50-18. The original Front tire on my bike is a Yokohama "Trail Sport". I presume the original rear was the same.
I personally believe in not putting "too much tire" on bikes, so I rejected anything brands that did not provide a front tire 3.25 or smaller and a rear tire 4.00 or smaller. Frankly, in my opinion, even 3.25 is a lot of tire on these 1.60 stock rims.

Note that I did not check the actual availability on all of these.

Shinko 244 Series   Front: 3.00-18    Rear: 3.50-18    Modern look "knobby" dual sport tires

Shinko 241 Series   Front: 3.00-18    Rear: 3.50-18    Similar trials type appearance to the original Yokohama "Trail Sport" tires

Kenda K270    Front: 2.75-18    Rear: 3.50-18    Modern look "knobby" dual sport tires

Vee Rubber VRM022   Front: 3.00-18    Rear: 4.00-18    Modern look "knobby" dual sport tires

Vee Rubber VRM022    Front: 3.00-18    Rear: 4.00-18   Similar trials type appearance to the original tires

Heidenau K37    Front: 3.25-18    Rear: 3.50-18    Modernish Trials Tires

Mitas H-03 / Sava H-03    Front: 3.25-18    Rear: 3.50-18  Street tires for rough roads. 

I chose the Shinko 241 Series. I'll post some pictures when I get them.

1973 Yamaha 175 CT3 Enduro - The next project!

When I was a about 11 years old my neighbor got one of these and I was really jealous. There was no chance my parents were getting me one!

It took until my senior year in high school in 1981 when I bought a street bike, a Kawasaki KH250 Triple, before I became a motorcyclist.

At any rate, the 1973 Yamaha 175 CT3 was imprinted on my memories.

After a long search I just picked one up this morning! It's low mileage and undented, but rather crusty. I'm excited to get it back running.
I scoped the cylinder through the spark plug hole and it looks OK in there and it turns over fine.
I have some other projects in line first, but then I'll clean the tank and carb, change the oil, and check the Yamalube system and see how it runs.
I'm excited!

More pictures:

Wednesday, October 10, 2018

Motorcycle Tank Rust Removal with Evapo-Rust


You can see a thin layer of red rust on most of the inside.


Much better! Almost all of the rust is gone. You can see some pinkish paint overspray on the inside of the tank, don't confuse that for rust. Whoever painted this tank must not have masked off the filler opening. The red oil in the bottom of the photo is some Marvel Mystery Oil I used to prevent rust.

What I used

I found this stuff called Evapo-Rust that had good reviews. I had used it on a couple items and was very happy with the results so I decided to try and use it on the inside of my Mondial gas tank.

The manufacturer of Evapo-Rust claims it is relatively safe. This is from their website:
"Evapo-Rust® rust remover is safe on skin and all materials except rust! It's also biodegradable and earth-friendly. Water soluble and pH-neutral, Evapo-Rust® is non-toxic, non-corrosive, non-flammable, and contains no acids, bases, or solvents. Evapo-Rust® is simply the safest rust remover."
They also claim is is safe on paint:
Powder coating and paint will not be removed as long as the paints do not contain oxides.
However, NOTE the exception they mention about oxides! Some paints do contain oxides, particularly red paints. Use care, especially around red paint.
I also saw it damage the clear coat on some of my decals. I was able to clean this up on my tank without trouble, but you should be careful!

My Mondial gas tank is 16 Liters or 4.2 Gallons.  Conveniently, the Evaop-Rust is available on Amazon in various sizes:
Evapo-Rust 1 Gallon

Evapo-Rust 5 Gallon Pail

Other items I used:
90% Isopropyl Alcohol to help rinse out the tank.

Marvel Mystery Oil to coat the tank after cleaning to prevent rust.

How I did it

I took the tank off the bike and removed the petcocks. I've heard people have done this with the petcocks installed but I didn't see any advantage to trying that. I made two petcock hole plugs out of a pair of bolts that I shortened and some rubber washers. I also used some teflon tape to help seal the plugs.

I put some plastic down and used a aluminum turkey roasting pan to catch any drips. I also put some blocks under the tank to hold it off the bottom of the pan. I made sure the top filler of the tank was perfectly level so I could fill the tank completely.

After filling the tank, I made sure the outside of the tanks was completely clean and that the was no evapo-rust on the outside. I didn't want any chance of damaging the paint!

And then I left the tank for a couple hours. I'm not sure exactly how long, but it was more than 2 hours and less than 4.

I've seen metal "flash rust" quickly after de-rusting, so I really focused on completing the next steps quickly.

When I decided the tank was "done", I emptied the tank into a large plastic bin so I could recover the Evapo-Rust for future use. And the I immediately washed the outside and inside of the tank with water. (It was really nice that the Evaporust is biodegradable, minor spills were no concern!) 

After shaking the tank out I put in about a cup of 90% rubbing alcohol and shook it all around and then drained that. And then I repeated that again with another cup of alcohol. The idea is the alcohol blends with any remaining water and then dries out quickly. 

But I was still concerned about flash rust, so after shaking out all the alcohol I could I immediately poured in about half a cup of Marvel Mystery Oil and shook and tilted the tank every possible way to coat the entire inside. I poured out the oil and repeated this step again with fresh oil. After the second oil coat the excess oil poured out looking nicely unpolluted with water or alcohol.
(Note: I wouldn't count on Marvel Mystery Oil for long term rust proof storage of an empty tank. But for short term use before filling with gas it is good. Marvel Mystery Oil is commonly used as a fuel additive and it a pleasing peppermint smell.)


I think the tank came out very well. Most of the tank looks great. That might be a bit of rust left in the bottom, I probably should have left it a bit longer or maybe rinsed it once and refilled for a second Evapo-Rust treatment.

I'll be curious how long this lasts. Some say they you should use a treatment that leaves a coating to protect the tank from rust, they tend to recommend a phosphoric prep and etch. I have done that in the past, but dealing with the acid is very hazardous! This Evapo-rust is much easier. As I said, we will see how it lasts!

Friday, October 5, 2018

Pi-hole advertising blocking and DNS - a complete kit

I decided to build a Pi-hole to block advertisements from our home network and so I could use it as a separate DNS server from our router. I set mine up on a Raspberry Pi 3 B+ that sits headless (without monitor, keyboard or mouse) next to my router.

Detail on technology: Pi-hole and more mmm-pi-hole.
Detail on the Raspberry Pi Hardware: Raspberry Pi.

As I built this thing I discovered a few things so I thought I'd share some tips. These are not detailed directions, just a basic outline of what worked best for me. If you know your way around this kind of stuff (setting up DNS servers and home routers) it will probably be enough, but if you don't, consider finding a more detailed guide than this one! 

Here is the hardware I chose (with pricing today 2018-10-5):

Raspberry Pi 3 B+ Motherboard $40
Power Supply with switched cord $10
32GB MicroSD card and adapter $9
Flirc Aluminum case with integral heat sink $16

Total cost: $75
(You will also need a monitor with HDMI cable and a USB keyboard and mouse.)


  1. First you need to format the SD card as FAT32.
  2. Next you need to install an operating system image on the SD Card. Raspian (Debian for the Raspberry Pi) is the obvious choice. Most of the directions recommended using "NOOBS", an installer program, but I found it set up a corrupt image on my card, and googling showed many people had problems with this. I tried the alternative method and actually found it to be much easier and I highly recommend it:
    1. Download Etcher (the image flasher)
    2. Download Raspian Stretch with Desktop (the OS)
    3. Unzip the Raspian Image
    4. User Etcher to Flash Raspian onto your SD card.
  3. Put the SD card in the Pi motherboard and connect the monitor, keyboard and mouse. Power it up!
  4. Once you have configured Raspian, you need to install the Pi-Hole software. Follow the directions on the Pi-hole website, its easy.
  5. Note, if you configure the Pi-hole initially for wifi, wlan0, it will not work over a wired Ethernet connection! You will have to go back and change the connection to your wired Ethernet port, eth0 or to "all interfaces".
  6. Configure the Pi-hole DNS as you desire. Be sure to note the password! You will need to assign it a static address on your network (see your router configuration for that) and point it at the appropriate upstream DNS servers of your choice. If you stream video services, I recommend using the servers assigned by your ISP or some other quality local server. Good article on CDNs and DNS.
  7. After power cycles, Raspian and the Pi-hole application seem to boot automatically. So you won't have to login or start the Pi-hole application manually after every reboot.
  8. If you want to operate the Pi without an attached keyboard or monitor, you can enable the VNC server built into Raspian. You can find this in the "Raspberry Pi Configuration Menu" under "Interfaces". You will need to install the VNC client on whatever device you want to use to view the server. Hard core users can enable SSH if they wish.
  9. Note you can access the Pi-hole software from any device on the local network by entering it's address in your web browser.
  10. At this point I tested the Pi-hole by telling a single computer to use it for DNS. When I was happy with how that worked I then changed the DHCP DNS settings in my router to enable the Pi-hole for the entire network.
  11. It works great!
I will note; there is not much visible improvement on a computer for the end user over something like uBlock Origin. However, the Pi-hole works great for smart phone and tablet users! And while it doesn't appear much different to computer users, it does substantially cut back on network DNS requests. The results are visible in the picture at the top of the page.