Just a little update on some of the winter projects I’m working on.
A little bit of TLC for the Tomos
In my previous post you saw I had a suspicion that my tomos had an air leak so I built a leakdown tester. Much of the leak was coming right out of the spark plug hole so I chased the threads with one of these thread chaser thingys and it worked like a charm, no more leaks. I’m sure I’ll have some carb tuning todo in the spring, but it’s hardly worth working on now while it’s so cold out.
Next up I decided to upgrade the front forks with some suzuki K10 forks for a cheap hydro setup. If I had to do it again I’m sure I could do it faster, but it’s a lot of tweaking to get them working on a Tomos. For starters the head tube on a tomos is pretty long, I removed the top cup from the head tube using a headset cup removal tool. Then I cut the head tube down using a sawzall right where the weld is on the top of the tube. The diameter of the tube is about 2mm narrower below the weld so I used a lathe and made the cup a little smaller.
The forks are setup to use 3/4″ handlebars so I had to dremel them out a little bit to use the 7/8″ M bars I picked up. The eyelets needed to be widened out a little bit in order to take a 12mm axle, I did this using a 15/32″s drill bit and since these forks are wider I had to pick up a new axle. I have to tweak the spacers a little bit before I call it finished. I believe it’s recommended to use a 5mm spacer on the brake side and a 14mm spacer on the other side.
I made a little plate that mounts on the top of the triple tree to hold my trail tech, I think it works out quite well. I also made a little mount for the speedo magneto sensor and welded it to the bottom of one of the struts. It’s fine for now, but my wheel is actually on backwards, the brake stop is on the wrong side, it’s easy enough to swap the struts and flip the wheel, but I’ll need to relocate the sensor when that happens.
If I had to do it again I think I might go for some kx80 forks, they’re longer in the triple tree department, they’re lighter, and you’ve got the option of running a disk brake. I’m thinking it would be less work.
Pinto Top Tank Project
I’ve got a pinto that I’ve been work on from time to time as well, this one did get a set of kx80 forks, they’re very awesome. I’ve shortened them around 5-6 inches by chopping down the springs and moving them over to the rebound side of things as shown in this picture
I also have a gas tank off a a 60s Montgomery Wards Riverside/ Beneli Fireball that I’ll be using on it.
The first thing I wanted to do with the tank is to cut out the existing petcock connection, it was an odd size and switch to something more common and easy to get cheap petcocks for. I decided to go with a Harley Davidson Petcock since they used the same 22mm petcock from 1975 to 1995 so without too much searching you can get them for around $10, so I picked up a bung and took out the existing petcock adapter with a 7/8″ holesaw bit. I have some pinholes in the tank as well, it’s pretty rusty so I figured while I braze the bung on I’ll also fill in some of the holes. This is the first time I’ve tried brazing with a MAPP gas torch, it doesn’t work the greatest, but it worked well enough to get the job done.
Note: The tank has sat empty of fuel for many years and I derusted and flushed the crap out of it, before I took the torch to it.
Since I’ll be using clip ons instead of standard handlebars on this one I’m going to be mounting my trail tech using the handlebar bracket on the top of the triple tree. Other then that I’m waiting on some new seals so I can finish those forks up and move on to other things.
Motobecane Pull Start
I picked up a pull start for a GS Moon pocket bike to use on the motobecane. They’re fairly inexpensive around $15. This will allow me to do away with bump starting and I should be able to ditch/plug my decomp. I’ll post more on this once I start working on it.
Swinger Ignition Troubleshooting
My wife’s bike cuts out at around 30mph, I think it’s either a bad ground, ignition coil or cdi. This should be too bad, but I haven’t gotten to it yet.