• Approximately 12.0" long
• Installation Instructions 

CHT Thermocouple Probes 
Includes fire sleeve and ring terminal hardware. Two different mount styles are available:

Bayonet Mount
These twist and lock into a screw-in adapter. The probe is spring loaded to ensure contact with metal instead of air. Choose bayonet style if the engine model is equipped with threaded thermowell receptor and/or bayonet adapter in the cylinders.

Gasket Mount
These do not require a screw-in adapter. The 18mm gasket fits on many common spark plugs. Some engine designs, such as radial engines, the O-235 and O-200, may prevent the use of bayonet style or may not allow for the use of a bayonet adapter. Choose gasket style if the engine model is NOT equipped with threaded thermowell receptor and/or bayonet adapter in the cylinders. 

*A new installation of P/N 86251 requires P/N 28202 as well.

** Does not require bayonet adapter. Screws directly into the thermowell.

For more information on probes, go to Thermocouple Probes.

ALCOR Instruments and Probes

Don't waste your money on cheap instruments and probes. There is a big difference!

Increase engine life and enhance safety through proper monitoring

• Faster responding probes than low dollar alternatives
• Temperature compensated gauges for accuracy all year round at any altitude
• Single gauges monitor one cylinder, dual gauges for twin engine aircraft monitor one cylinder per engine. Add a selector switch to make an economical full engine analyzer. Lighted gauges and custom dials also available!

Alcor: A name you can trust

• Over 50 years experience - Designed, manufactured and supported in the USA
• Generous warranty: 3 years for gauges, 5 years for grounded probes, 1 year for ungrounded probes
• FAA-PMA/STC approved for all aircraft with reciprocating engines

Simple installation

• No power required from the aircraft (lighted gauges require power)
• Works even with an electrical failure
• Great for homebuilt or antique aircraft with no electrical system
• Gauges include all mounting hardware
• Standard 2 1/4" or 3 1/8" gauge sizes

Save with complete kits!