i've got a 1/5 scale onroad with a zenoah engine this weekend... the engine does't have any name or numbers, i just want to know what should be a good operating temperature ... i'm familiar enough with 1/10 scale size engines.. so far we're just tuning by ear...

If you run it on the "slightly" rich side and make sure it has plenty of air for cooling you really don't need to worry about temp #'s The problem with temp #'s is that it only really matters when you are pulling hardest in the air, can't use any IR gun for that. You could use a data logger, but why. Unless you are really into competition or just like to tinker. I guess we all like to experiment in this hobby though.

Now that I read your original question again I believe this should go into the "cars" forum.
Oh by the way what is a 1/5 scale onroad? Buggy/Car? Showing my ignorance now. Tuning by the ear is a great way to set up engines if you know what you are hearing.


Ralph