Re: Fellow Opti-2 users please help me out!
Probably cheapest to buy the temp gauge and the sensors separately.
The temp guage was about $5 on Ebay from China.
The sensors were about the same, again from China on Ebay.
Locally the sensors were quite dear.
The sensors I got also required the right plug for the guage. another $1?
I tend to prefer my IR (point and shoot) temp sensor however, which was also very cheap from China on Ebay and has multiple other uses. But requires pulling over and should be done immediately, as the motor starts to cool quickly.
Once the motor is set up there should be no real need for a temp gauge on most builds, but great tuning aid.