Trouble with my Saito FA62. Been flying my Hangar 9 Piper J3 Cub for a few years now with a Saito FA62 four stroke engine. Was running great for a long time. But recently it’s been stalling when the tank gets to be about halfway full, or halfway through a flight. Well, I did a lot of searching online and checking RC Plane Forums such as RC Universe and RC Groups for some advice and I got a few nice viewer comments with some tips (thanks!). The popular advice was that there must be a leak in the fuel line inside the tank that when the fuel drops to half tank, the line draws air which leans the mixture and stalls the engine. This made sense to me. So, I checked the fuel system and replaced all the fuel lines and installed new Dubro tank, but nothing stood out as a problem (see the last video on this: Part 2).

Then I decided to check the glow plug. Based on my evaluation, it appeared that the glow plug was not as powerful as it should be and was worn out. So I replaced it with a new OS Engines Type F glow plug.

Next I set the valve lash or the valve gap of the Saito FA62B, also known as the tappet adjustment. I use a standard automotive feeler gauge to adjust between the valve stem and the rocker arm. I finish up by placing some Marvel Mystery Oil down the push rods and installing the rocker arm, or valve covers.

In this video I do a test run on the Saito FA62 using VP Powermaster fuel and a Master Airscrew 126 propeller. I show how to adjust the high speed needle and the low speed glow fuel mixture settings for the carburetor and set the RPM for proper idle and up to full throttle. Setting up or tuning a four stroke rc glow engine can be a little tricky so I hope my video is helpful or at least a little entertaining.

I have been building, flying, crashing, modifying, and repairing radio control planes (RC Planes) for many years and enjoy sharing what I do with the radio control plane community, so I started RC Plane Tech channel for fun. I am not an expert, there are many different techniques to building radio control planes. A good way to learn about flying and building rc planes is to see what others are doing, that's what I do and that's why I like to share what I do. Thanks for watching my channel. Have fun!