XR 250, 400 Normal Engine Temp Post!!!!!!

I tried something different, I hooked up my trail tech temp sensor like a washer on my header head bolt. Is this going to be a good indication of accurate engine temp????? What's the 400's normal temp range??

When riding it reads around 280 F

When sittting at idle it goes up to about 330F

It should be an accurate reading of cylinder temp right? Isn't cylinder temp better than the oil temp in the engine???

What's your guys average riding temps??????????

Post em !!!!!!!!!!!!!!!!

Sensing temp at the header bolt isn't common so your values won't compare to values obtained at other locations. The most common probe point is under the plug washer, second a cylinder head bolt. Using one of these points allow like to like comparison with values from other riders.

considering all of the heat near the header 280 isn't bad for cruising. The big jump when stopped illustrates why you should never stop and idle a hot air cooled engine. I measure mine under the spark plug and it is amazing how hot the head gets on a long slow mountain climb.

A cylinder heat temp is faster to react to changes in operating conditions than oil temps. I also have a XRsOnly dip stick oil temp gauge on my XR and found the results a bit different than I expected (cooler).

Normal operating temps for the oil on the 400 are around 220. I don't think the head temp reading I get from my Vapor is accurate because of where I have it mounted, which is the upper engine mounting bolt. I'm sure the brackets act like a heat sink. I need to find a better place for it.

I have an xrs only dipstick...

200-225 ormal riding temp... up to 260 when riding hard?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now