There are many good break in procedures out there that we feel work well. Our standard break in procedure for a resizing with medium tightness is a 4-5 heat cycle method at 200-220F (covering engine if necessary) followed by 4-5 easy tanks on the track at half throttle. Note: A tight resizing requires more time on track running before tuning for performance.

Remember to bring engine immediately up to temp the first Start of resized engine, and each time there after.

  • We recommend 210F or slightly above each break in cycle.
  • Use tin foil to cover the heatsink to assist in brining the engine up to temp if needed.
  • Always bring piston to BDC and cool between tanks.

Before tuning for performance it is best to remove the glow plug while engine is at operating temperature and test the tightness at TDC. With your finger on the flywheel, you should be able to roll the piston past TDC with very minimal resistance. We find that after 1-2 liters of fuel usage our engines loosen up as with a new engine and are where peak performance occurs.

Remember you are running a previously worn engine that may require attention on other internal moving parts.

  • Check your bearings for lateral movement or noisy sounds that indicate a dirty or worn ball bearing that may need to be replaced
  • Check the conrod, wrist pin, and crank pin for excessive wear. It is always good standard procedure to replace the conrod after initial break-in, as they are the next least expensive to replace next to resizing your piston & sleeve set.

Below are published break in procedures we feel work good: