YAMAHA Trail
250 DT-1 1969 Vol.16 Troubles that occur immediately after restoration = Yamaha Trail DT1 that has been racking up the mileage for umiage The other day, a fellow motorcyclist who had left his vehicle with us called and said, "Rust is becoming noticeable.... ...". When I assembled it, I thought "machined stainless steel parts, maybe polished ......", but the cosmetic rings on the light stays
were covered with rust before I knew it, so here I'll
make machined aluminum parts to prevent rust.
Maintenance lifter makes "bike tinkering" fun.
Early series DT1s with front forks that cannot be extracted due to a step in the top bridge without loosening and removing the top bolt; the front area is not as easy to service; the front fork is not as easy to remove as it was on the earlier series DT1s.
![]()
A maintenance lifter for motorcycles would make a big difference in "workability" and, naturally, motivation. Previously foot-operated, the company now has electric hydro lifters.
When crafting parts, the "machine tool" as it is called, shows its power
![]()
The genuine Yamaha parts are die-cast parts made of antimony material with a chrome plating treatment, but here the cosmetic collar was made by machining a lathe from an aluminum 2017S muku bar.
![]()
The aluminum decorative collar (left) was machined and fabricated while reproducing the dimensions of the steel parts. Since this is not a sliding part, there should be no problem with aluminum parts. Did the parts that started to rust forget to be plated?
One assembly and restoration procedure can change the "operability" and "touch" of the product.
![]()
The top bolt to be removed interferes with the handle and cannot be pulled out. I had no choice but to pull the top bolt out with the handlebars in the air and pull the inner tube down.
![]()
The forks were pulled out one side at a time and restoration began while replacing the cosmetic rings on the light stays. When restoring the fenders, the axle shafts were inserted and tightened and built while restoring the fenders.
![]()
When restoring the front wheel, the axle shafts are tightened while maintaining a firm grip on the brake lever after temporary assembly. This centers the brake panel.
![]()
Once the front axle is tightened, let's float the front wheel and spin the wheel. Tapping the axle shafts from both sides with a plastic hammer will allow the bearings to settle down and rotate smoothly.
Driving vibration causes "blinkers to blink erratically."
![]()
The old indicator relay, which had been bothering me for some time, was replaced with a 6V-spec IC indicator relay. It would be nice if the blinker blinking speed would be constant even at high RPM when there is a lot of vibration. ......
![]()
The blinkers blinked normally during normal driving, but when the car is idling at a traffic light, the speed of the blinking is unstable.
![]()
All 6V8W indicator bulb bulbs were replaced with new parts. If the deteriorated bulbs are used in pieces, the brightness may vary from front to rear and left to right, and the blinking may become unstable.
POINT.
- The point of full restoration・After the almost full restoration is completed, the process of actually running the car to identify defective items is commonly known as "umidashi test run. Since unexpected problems and defects may occur in the early stages of assembly and restoration, repeat the test run to troubleshoot the problems.
Air-cooled 2-stroke models tend to have unstable idling due to overheating in summer. When we ran Mach III and H2 on a very hot day, it was very difficult. In particular, the shuddering sensation at low speeds in the H2 was a painful experience that we hated to endure. After that, we had a chance to meet with a parts constructor and were able to participate in the development of a piston kit for the H1 and H2, and after the new pistons were installed, we were able to drive comfortably.The "Dream Timer Piston" made by Shift Up, which is now used by many users all over the world, is just that. The users who have installed these piston kits will understand the beauty of this piston kit. We were reminded once again that when the piston clearance is set to the specified value, the running condition improves as well.When we installed the "ICBM® with columns" into the intake and exhaust ports, an advanced version of the "ICBM®" with special plating on the aluminum sleeve, we were convinced that "this is the only way" for 2-stroke sports model engines, whether air-cooled or water-cooled. I was convinced that this was the only way to go. It is a very quiet engine. When the owner of a Yamaha DT1 who lives nearby came to visit me at my garage, as soon as he heard the sound of the ICBM® Mach engine, he said, "I wonder if my DT1 will be like this! He said, "I wonder if my DT1 will be like this!In this DT1, we challenged "ICBM® with columns" on the intake and exhaust ports and obtained outstanding results. The DT1 was running around in the summer because it is easy to see the difference on extremely hot days, but with the ICBM® with column, the difference is clear. The ICBM® engine with aluminum-plated cylinders keeps a stable idling even in midsummer or in extremely hot weather, so waiting at traffic lights is not a problem for the driver.Now, due to such long summer and fall rains = humidity, we were informed that the "rust on the ring" that mounts the light stay "started to show and ......". When we procured the parts, we were told that the parts were machined from stainless steel rod and buffed to a shiny shine.However, it was clear from the rusting that the parts were buffed iron parts, as if they had used the wrong material or forgot to ask for chrome plating. The iron parts for chrome plating may have been mixed in with the buffed stainless steel parts. When I checked them with a magnet, they were vigorously attracted to the magnet.Since the rusted parts were conspicuously uncool, we replaced them with parts machined from aluminum rod in the same dimensions and buffed and polished to a finish. This settled the matter.Image gallery (11)
49
0
Share 
Copy link
X
Facebook
Save
![[Overseas] 2027 New Model "Ninja ZX-6R" Appears in North America! New Galaxy Silver/Twilight Blue Colors Refresh Lineup](https://news.webike.net/wp-content/uploads/2026/07/google-g-icon.png){kind=icon}
