Hello everyone,

I have been flying for about 5 or 6 years and over that time I have always owned used planes and never had to do an "Engine Break-in"

I bought a Pulse XT 125 and after all the parts I could only afford the cheap Evolution 120NX
(everyone says it's an ok engine and pulls the Pulse 125 around nicely)

I spent 2 hours reading all the posts (back to like 2006) about Ringed Engine Break-in, There were a lot of fights and arguing

The manual is seems kind of vague (and goes against what some people here say)

I don't want to start another argument, can someone look at the text from the manual below and tell me if I should do the Engine Break-in the way stated in the manual?

THANKS !

Joe

TEXT FROM MANUAL:

Engine Break-in
Ringed engines need a different break-in procedure than a typical ABC-style piston and liner construction. The component that provides the compression seal is a spring steel ring that needs to fit itself to the minute scratches on the interior surface of the cylinder liner. With care in this process your ringed engine will last a very long time. If you ever notice that the power seems to have dropped on your EVO 1.20, a quick installation of a new ring and a new break-in period will restore your engine’s health to near-new condition.

1. Mount the engine on a test stand or in the airplane you intend to use the engine in. If there is cowling around the engine, it would be a good idea to do the break-in process with the cowl removed to allow adequate access to and cooling of the engine.

2. Fill the fuel tank with the fuel you intend to use (10–15% nitro).

3. Start the engine and leave it running rich, with the glow igniter attached if necessary.

4. Open the throttle wide open, and let the engine run at a rich ‘4-cycle’ (where the engine actually doesn’t fire each and every time. With experience you will be able judge this easily. For those new to nitro engines, you will hear a sharp increase in rpm and sound when the engine transitions from a ‘rich 4-cycle’ to a 2-cycle run). Let the engine run through the tank at this setting, or at least 10 minutes, then shut it down and let it cool completely.

5. Restart the engine, but this time to vary the needle settings, with brief periods of 2-cycle running alternated with longer periods of 4-cycle running, through the next tank of fuel for at least 10 minutes.

Note: A good way to judge the time limits for the 2-cycle and 4-cycle running periods is to touch the cylinder head with a free finger while adjusting the needle valve. When the engine is at a 2-cycle, you want to richen the mixture when you can no longer touch the side of the cylinder with your finger. Conversely, the engine has cooled enough when you can touch the cylinder comfortably.

6. Repeat Step 5 one more time and then the rest of the break-in can be accomplished in the air. Set your engine’s needle valves per the instruction manual. If anything, continue to err slightly on the rich side and your engine’s performance will continue to improve over the next gallon of fuel or so.