Safe Temp of air cooled motors

Rule308 · 10-18-2015, 04:15 PM

I bought some stick on thermometer strips that read temperature. I believe they are for water cooled engines though and don't go to high enough temp. Does anyone know if there is a general do not exceed temp measured on the cooling fins for an air cooled motor?

Mudflap · 10-18-2015, 05:29 PM

It's at least 450 degrees F. That was the limit for the old VW. The forced air cooled 2 stroke Rotax 503 aircraft engine is 425 measured at the base of the spark plug.

Weldangrind · 10-19-2015, 12:26 AM

I had no idea that air cooled engine temps could get so high!

Mudflap · 10-19-2015, 09:43 AM

I believe these engines are the same ones used in many of the 3 wheel rickshaws and mini trucks in Asia and the Middle East. No doubt they spend lots of time in grid lock traffic in hot weather and still hold up well. IMO the main potential problem is breakdown of the oil at high temps. Synthetic oil in general can withstand higher temps without breaking down.

Weldangrind · 10-19-2015, 03:07 PM

Most of the three wheeled trucks I've researched have been CG-powered, and several of those have had an external oil cooler installed. I'm toying with the idea of an oil cooler as well.

Rule308 · 10-19-2015, 06:57 PM

Dipstick thermometer. Seen some that are in Celsius, but I don't have a feel for Celsius might as well be Ohms or Angstroms.

If anyone finds a Dipstick thermometer please post it.

Weldangrind · 10-19-2015, 08:30 PM

If you can't find a Fahrenheit thermometer, Celsius can be converted easily enough. Take whatever the Celsius number is, double it and then add thirty.

Eg. Room temperature is about 20C. 20 x 2 = 40, + 30 = 70F. Close enough.

Mudflap · 10-19-2015, 09:02 PM

You can make your own from a $6 digital food thermometer from Harbor Freight.

Rule308 · 10-19-2015, 09:51 PM

That's something I'd do. Does anyone know if any Honda XR models share same oil dipstick?

http://www.xrsonly.com/parts-categor...ure-dip-sticks

Weldangrind · 10-19-2015, 11:53 PM

My guess is that an XR200 dipstick would work in a CG or CB motor.

10-18-2015, 04:15 PM	#1
Rule308 Join Date: Aug 2015 Location: Houston but will ride in Llano Texas Posts: 52	Safe Temp of air cooled motors I bought some stick on thermometer strips that read temperature. I believe they are for water cooled engines though and don't go to high enough temp. Does anyone know if there is a general do not exceed temp measured on the cooling fins for an air cooled motor?
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10-19-2015, 12:26 AM	#3
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I had no idea that air cooled engine temps could get so high! __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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10-19-2015, 03:07 PM	#5
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Most of the three wheeled trucks I've researched have been CG-powered, and several of those have had an external oil cooler installed. I'm toying with the idea of an oil cooler as well. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

10-19-2015, 06:57 PM	#6
Rule308 Join Date: Aug 2015 Location: Houston but will ride in Llano Texas Posts: 52	Looking for a Dipstick thermometer. Seen some that are in Celsius, but I don't have a feel for Celsius might as well be Ohms or Angstroms. If anyone finds a Dipstick thermometer please post it.
	0

10-19-2015, 08:30 PM	#7
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	If you can't find a Fahrenheit thermometer, Celsius can be converted easily enough. Take whatever the Celsius number is, double it and then add thirty. Eg. Room temperature is about 20C. 20 x 2 = 40, + 30 = 70F. Close enough. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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10-18-2015, 05:29 PM	#2
Mudflap Join Date: Sep 2014 Posts: 1,870	It's at least 450 degrees F. That was the limit for the old VW. The forced air cooled 2 stroke Rotax 503 aircraft engine is 425 measured at the base of the spark plug.
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10-19-2015, 09:43 AM	#4
Mudflap Join Date: Sep 2014 Posts: 1,870	I believe these engines are the same ones used in many of the 3 wheel rickshaws and mini trucks in Asia and the Middle East. No doubt they spend lots of time in grid lock traffic in hot weather and still hold up well. IMO the main potential problem is breakdown of the oil at high temps. Synthetic oil in general can withstand higher temps without breaking down.
	0

10-19-2015, 09:02 PM	#8
Mudflap Join Date: Sep 2014 Posts: 1,870	You can make your own from a $6 digital food thermometer from Harbor Freight.
	0

10-19-2015, 09:51 PM	#9
Rule308 Join Date: Aug 2015 Location: Houston but will ride in Llano Texas Posts: 52	That's something I'd do. Does anyone know if any Honda XR models share same oil dipstick? http://www.xrsonly.com/parts-categor...ure-dip-sticks
	0

10-19-2015, 11:53 PM	#10
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	My guess is that an XR200 dipstick would work in a CG or CB motor. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0