Anyone ever check the engine temp with a infrared gun?

I was checking the engine temp and the engine cooling fins are at 230-240℉. Is there a standard out there. The engine doesn't have any characteristics of running hot? It does seem a little high though? I would think that it would be around the 190-200℉? I'm not sure of the oil temp at the moment.

 

It's been reported here multiple times on airheads, can't remember a water cooled report. For airheads-oil temp will range from around 180F at first warm up to 270F on a hot day waiting in traffic. The oil temp can go higher but it really shouldn't as it will start to break down and lose viscosity over 300F, unless it's synthetic. But the synthetic limit is mute in an XJ airhead because if the oil has topped 300F you have other problems coming fast.

Your cooling fin readings are not unusual, but they are dependent on several things, the motor, the ambient temp and humidity, the style and time of riding prior to reading, the condition of your oil and fuel mix etc. I've never heard of an airhead that will run below 200F at its fins once it's fully warmed up. Most I've seen measured come in right around 200F as you stop flowing air and will rise to 220-250F shortly thereafter.

You can check other 'low-tech' signs that your running too hot, like bluing pipes, rapid pinging on shut down, oil that looks black way too soon, aluminum specs on your plug bodies, idle stumbling and depressed, other symptoms of being too lean, or bike dies unexpectedly. :cry:

 

Thanks for the info. I have a service manual and there is no information on this. I hope this helps other guys out there too.

 

How Hot is Hot?:

The following information was measured on a stock, un-modified XJ650 YICS engine, with the air temperature between 60- to 70-F. Modified engines, engine tune conditions, different air temperatures and humidity levels, etc. will affect these readings up or down.

Using our HCP9959 Digital Infrared Heat Thermometer, we verify that the cylinders and the valve cover are the hottest part of the engine, with the front of the cylinder jugs (exhaust port side) reaching almost 390-F during and immediately after spirited riding, while the intake side of the cylinders were consistently 50-degrees cooler (350-F). Cylinder heads, surprisingly, remain much cooler, just barely breaking the 280-F mark.

Engine upper case and engine side covers vary in their readings depending on which cover and where on the engine case the reading is taken, but in all cases are substantially cooler than the cylinder head, valvecover, or jugs.

Brake rotors were measured at 300-F or more after 10 consecutive maximum-force braking events from 50mph. Calipers were approximately 50-F cooler.

Rear final drive units are like refrigerators, and were never measured at over 140-F.

 

THIS GREAT INFORMATION!

I can now know that my bike is running within temp range. I'm messing a lot with fuel requirements and timing. Running on microsquirt fuel injection.