My Honda GX50 engine conversion to RC
 

Hi guys!
As we all know, there is a joint venture factory with Honda in China, we can buy the short body assembly of the GX50 four-stroke engine for maintenance part in the aftermarket, the price is very cheap. So, there is no need to buy a used Honda lawn mower or other hedge machinery on the second-hand market, and then remove a lot of unwanted parts in order to get the main engine that can be used and cause a lot of waste. I have long heard that this Honda GX50 engine can be conversion for use in model plane engines, and is a good power for World War II like scale model planes or large aircraft, I can remove its oil pan and burn mixed oil. This is indeed a very good choice. So I'm going to try to do this...
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I learned that a friend of mine, Mr. Yao, who runs a car repair shop, is also a model enthusiast of his own, and knows very well how to modify engines such as GX50 into model aircraft engine. So I wanted to ask him for help, because he had some metal materials and machine tools to make some small parts necessary for modification.
When Mr. Yao got my short body engine, he was very skilled at dismantling it, and surprisingly quickly cut off the unwanted parts with a grinding wheel Angle grinder. He was very skillful and knew exactly what was to be kept and what was not useful.
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My God, it looked like this in less than an hour! As you can see, there was a huge oil pan, and like most four-stroke engines, the oil was separate from the gasoline, but we decided to burn the mixed oil in the future, so the oil pan was useless, and when we cut it off, we lost a lot of weight, and this engine had a timing belt soaked in the oil, and when we cut the oil pan off, Also cut the lid off the timing belt box so that it is completely exposed and becomes a dry belt.
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We cleaned each piece, and the next step was to assemble an engine that could fly. As you can see, we have removed the third oil ring from the piston, leaving only two compression rings, so that we can burn the mixed oil. As you can notice, we cut off the oil stirring blade next to the crankshaft timing wheel, and removed the crankshaft rear oil seal.
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Ok, let's write here today, and look forward to assembling a real aircraft model engine that can fly to the sky, tomorrow!
Thank you all

Hi, Guys!
Today, I did some preparatory work before assembling the engine, and then I showed you what the engine looked like after assembly.
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As you can see, we have prepared four mounting pillars, a hub, a central screw for hub , a nylon carburetor interface pad (which makes the hole and channel of the vacuum pressure drive carburetor diaphragm), of course, replacing the original carburetor with a Walbro carburetor is recognized by modelers, and the original carburetor has a mechanical limit device, Inhibits the maximum engine speed. A crankshaft position sensor seat was built with nylon rods, the Hall crankshaft sensor was mounted on it, fitted to the crankshaft front bearing housing, and secured with a screw. The initial position of the sensor can be adjusted during the engine run-in test.
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Now, we can do the assembly of the engine. It is still very light and beautiful!
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OK, DONE! The exhaust pipe is simply a stainless steel bellows welded to a rhomboid flange, in order to hear the wonderful exhaust sound of a four-stroke engine. The pictures were not taken, and then I am going to edit some videos and you guys could see the engine in action.

The video come up, welcome to give advice.
I used a 19x8 propeller, and after fully break-in the engine, it is said that it can reach 7000~7200 rpm, which can provide 7~8kg of pull. I'm looking forward to it. I plan to put this engine on my 1/3 J-3 and will share its flight when the time comes...

I found another good thing, my friend made this GX50 exhaust pipe by himself, processed the exhaust pipe seat, silencer, connection bend, which is based on Saito exhaust pipe to make some improvements, the feeling is still good, using the M15X1 thread size, you can hear the pleasant sound.
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If anyone likes this exhaust pipe assembly, you can contact me...

awesome, that carburator series you use ? as for the CDI do you just use RCexl ones?

Can you contact me so I can purchase a GX50 flange from you. Thanks!