CHT & Coolant Temp

Did you recently retrofit the 'new-style' cylinder heads??  ( see https://www.rotax-owner.com/videos-topmenu/rotax-minute/448-newcylheads   and  https://www.rotax-owner.com/videos-topmenu/expanded-video-instructions/463-new-torque )

Hi,

We haven't retrofitted the new cylinder heads, so the two CHT senders must be reading the temp of the metal (photo attached)

However, it looks like a Coolant Temp sender has been retro-fitted (it's a Rans S6) to the engine appended to the coolant pipes? (see attached photos)

We have connected both CHT sensors to the same Instrument since it was just one extra wire, no big deal. A simple switch allows to change from one to the other sensor. Temps are very much identical and vary (most likely) by production variance, not worth mentioning. The use having both of them connected is limited. However, CHT is OK if one sensor reads an OK temp (thus, should one fail, the other one is of use). The readings of the two sensors ought to be very similar because of the  coolants flow speed. I'd say that aplies to readings of two coolant sensors, too.

Comparing coolant temp with CHT is almost comparing apple and pears. Choose either or and draw conclusions from sudden changes to the standard and you'll know what you need to know.

The more you put in the more can fail ;-)