Safe surface temp on head

[Toothy]

I've been drilling my jets and my engine seems to be running hot. I didn't pay much attention before so im not sure if this is a new 'issue' or not. Reading over 200'F after a good run using an infrared thermometer. Spit and sizzle. My plug is not white. black on the rings and brown on the tip...not a true chop test though.
Thanks.

 

[mew905]

only 200F? that's only about 97C, not even enough to boil water. Sadly ya gotta test mid-ride, the engine cools off quite quickly when its moving or windy.

 

[Theon]

With a shaved straight fire I'm getting around 150 C.
With a Puch I'm getting 130 C.
I've been told 200 C is about as Hot as you want to get,
With an angle fire I get around 180 C which to me seemed too hot, and was causing motor to 'Ping'.

 

[wheelbender6]

That sounds right. Nascar engines keep the head temp below 500 deg F.

 

[66sub]

grab the head if u can hold it for 2-5 seconds your ok. works for me and my gloves .

 

[Wild Bill]

The temp should be measured at the actual head surface near the spark plug and not out on the fins.

 

[Theon]

Checking head temp is cheap and easy.
The infrared thermometer was very cheap, but seems to be accurate enough.
However to get a comparison to check it by, I ordered a couple of thermocouples that mount under the plug washer, these are also cheap if willing to wait from China, although seem to be ridiculously over priced locally.
Once the motor is tuned and tested there is really no need to monitor the temp unless changes are made.
If your motor is too hot your likely to smell the oil burning off, but still good to be able to get a reasonably accurate reading.
My Soft tail had an angle fire head for a short time, and was getting a little hot, which was evident by the black stain to the underside of the piston crown.
If your going to try and get these motors to perform, throw away your angle fire head!

 

[Wild Bill]

66 sub, the temp out on the fins is after cooling has taken place, you want to know what the temp was before any cooling has taken place, that is why the digital temp gauges for kart racing and other air cooled apps mount the sensor and read the temp under the spark plug. Along with being wrong, in reading your previous posting history, you have a serious lack of maturity.