yeah.unscrew the spark plug and then put the head temp sensor in place of the plug washer and reinstall the plug.I used them for years on my karts and they are darn accurate...right up to the melting point of the piston reliable too as you can get digital head temp guages from Mychron or Digitron.they are vibration proof and water resistant but they make nice watertight covers to put on them.u can also get them with a TON of other options on the guage.speed,EGT,head temp,coolant temp,rpm,timers,backlighting,etc..they mount with a ball and socket setup similar to a RAM mount.