Today we’re gonna work on one of the world's smallest four-stroke engine, Semto engine ST-NF2, that actually work. It looks like a real engine and I will be showing you the parts and some assembling process and then starts the engine. You can download the assembling process and it's very easy to follow.
Let's start with the engine cover. Its impressive quality stands out, especially considering the engine's small size. this is the fuel tank which it will be filled with 20 to 25 percent of natural fuel.
This is the glow plug and it will do a spark plug job whenever the engine used Nitro Fuel and it has glow plug instead of spark plug. you don't need oil in that engine because Nitro fuel contains oil and it will constantly lubricate the engine. the engine comes with every Hardware you will need to assemble the engine kit and the tools to complete this build.
I will be using high temperature grease to lubricate upper part of the engine since Nitro fuel not can reach that part of the engine to lubricate camshaft and rocker arms.we also again need some conventional oil to lubricate the seals and the Pistons while assembling.I start the following process from crankshaft and lubricate every seal and bearing before putting everything back so I don't have problem with engine startup.
I recommend wear gloves while assembling the cylinder block is CNC machined and it has some sharp edges. the Precision of the parts looks very good and very precise with some oil lubrication. I didn't have to force any power to its place as you can see all the parts should get in place without any Force. otherwise you will damage them using oil with a strong which will make your job much easier and less messy. I can put few drops wherever I need and try to use thinner oil grade so it doesn't put any resistance on moving Parts. I'm using 0w20 viscosity oil which I used for my 2017 Toyota Camry and that is what I have in hand.
Right now I've seen some people using Torx screwdriver to make sure every bolt has same torque but I don't have any in hand, hoping it won't bear problem. the installation is very easy. just pay attention to the small details so you don't damage anything because it doesn't come with spare parts after putting the camshaft and crankshaft timing.
Rotate the camshaft, you should hear suction sound and smooth rotation. next I'm going to be using high temperature grease to lubricate upper part of the engine since natural fuel not gonna reach that part of the engine to lubricate camshaft and rocker arms. so I'm gonna put two drops of grease and separate it with a small brush. next carefully putting the gasket and lining up the holes and then the engine cover .
The Following part is very easy not going to be installed in a wrong way. it's self-explanatory even if it was wrong you can take it off and put it back again in a right way. it's not going to be like apart from the engine to disassemble. everything gone of the things I like about this engine that it has its own starter just like real engine most of small engines has puller handles to start up but this one has their own starter.
alright engine assembling almost done and it looks absolutely amazing even just like a model. next we're gonna put the glow plugs in and then the wires foreign Sketch Up and designer base for mounting the engine and the tank. after a few hours it's been 3D printed it will make everything organized and I don't have to hold anything.
I use four additional M4 screws to mount the engine and two screws for mounting the tank. next installing glue plug wires that looks like spark plug wires exactly and then start your wires. alright we are almost done the assembling. took two and a half hours plus moving camera and 12 hours of 3Dprinting the base for the engine.
one last thing installing the fuel line hose and I will try to make it short a s possible to make the engine easy to suction the fuel. alright guys we are outside and filling the fuel tank with the 25 percent of nitro Fuel and don't try to run this engine in a closed place. connecting glow plug wires to a 12 volt battery and starter wire to a 12 volt battery as well let's push the starter button and see how it works. the throttle it turned off. so let's start again and see if we can lower the RPM later. all right it runs much better now I can lower the throttle but it's on Ridge side and suction more fuel to the carburetor, I had to tune it later but overall it works really cool I'm really impressed with the function and detail of this engine.
As we've explored the world of this functional miniature four-stroke engine, we've witnessed the intricate parts, followed the assembly process, and experienced the exhilaration of starting it up. This remarkable creation not only mimics a real engine but also demonstrates impressive functionality. Whether it's the engine cover, fuel tank, glow plug, or meticulously lubricated components, every detail contributes to its realistic operation. These Semto engine kits help your students to combine theory with practical experience to provide them with the necessary skills to perform maintenance, tune-up, and repair of 4-stroke nitro-powered engines. a great gift for automotive technicians and professionals.
The assembly process, while requiring attention to detail, is made easier by the provided instructions. It's crucial to handle the parts with care, ensuring proper lubrication and avoiding any potential damage during assembly. The use of high-quality oils and greases, along with the right tools, enhances the overall experience.