Piston Stop For E25

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Part# 12-18100
MFR Model# E25-18


Hardened aluminum piston stop for the E25-9 timing indicator.
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Nice simple tool to find the real TDC. Found my TDC timing mark was 3 degrees off (can use smart phone fastened to prop with angle app)

David P
April 20, 2021


Please note, Pilotshop's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Pilotshop assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Regarding Part # 12-18100: I use UREM38E spark plugs and would like to know if the following part number will fit my 5/8 slot in order to find my number 1 cylinder top dead center?

This piston stop is the same thread, 18MM, as a Champion or Tempest plug that goes in the cylinder. We have added the E-25 user manual to the "Documents" tab of the web page should you need to reference it.

Q: Is this piston stop pin universal for ALL Lycoming and Continental cylinders? Will this stop contact TDC on all cylinders accurately?

Per the manufacturer: Yes the piston stop can be used for all engines with 18mm spark plug hole. Yes it will allow you to find TDC accurately.