Operating temperature range

Does anyone know what the safe operating temperature range for the 650R is? I have just changed to Engine Ice and feel the engine is running hotter :thumbsup: I am afraid that theEngine Ice raises the boiling point so I do not know if the engine is getting toasted. I am thinking about getting the thermometer oil dipstick or other thermometer to check the temp. What temp range is safe? Which temp would be considered too hot?

Thanks in advance


Get the temp dipstick. Im not sure bout the 650, but the 250 (air cooled) runs at 225-250 normally, 275 on realllly hot days. Runnin maxima %100 4 stroke synth.. :thumbsup:

I've got a 650L and those readings are the same i normally get. :thumbsup:

some claim the problem is the cooling system is not allowing the coolent to stay in the radiators/heat exchangers long enough to properly cool down...

For sure messing with the cooling system is a simple fix, but with a ripple that effects lots of other things...

I run the larger radiators, colder plug, thermostat removed. Low pressure cap. NEVER overheats! But is it running to cold? Could be....i've been thinking about some accurate temperature sensors...word has it the temp dip stick isnt that accurate-read past posts on here. But i havent tried one so dont know. Cycoactive sells temp sensors...

take a look at the srcinc.net site. They have some info and some products to consider--like a working thermostat and the temperature dip stick...180 - 300 degrees is your range.

For a good inexpensive 180F thermostat that fits without any tweaking, go to AutoZone and ask for part number: 457-180. It will cost you $4.99 :devil:

SRC gets their oil temp dipsticks from XR's Only. They're fairly accurate as long as they're properly calibtated and in good condition, but its not hard to digitally monitor oil temps with a much more accurate thermistor drilled / tapped into the left side frame plug. BBQ's Galore sells a mini digital thermometer with memory for $16. It can be taken apart and the thermistor can be relocated inside a drilled out 1/8 NPT fitting and wired to the display that can be mounted on a simple 'L' bracket from the fork tube clamps :thumbsup:

You can also do the same thing for the cooling system. There's a nice boss on the thermostat housing as if it was meant to be drilled and tapped for 1/8 NPT :awww:

I've written SRC twice asking them if they are sure that under 300 is considered "normal" and they haven't replied...

300 seems astronomical, even for an air cooled engine.

The oil will lose most of its characteristics in such a high temperature.

My XRL is running at between 175 and 200 all the time thanks to the oil cooler.

BTW, the cooler is from a KYMCO Heroism scooter, but you could install any cooler of that size.


I don't like SRC's oil cooler very much because it's installed behind the front headlight mask. It'll probably be more effective on a race bike that has a number plate instead of a headlight.

300 seems astronomical, even for an air cooled engine.

Yep, it's very high and it's one reason why oil doesn't last so long in some bikes in addition to shear. The oil temps on our XR250's can get to that temp and even higher in some situations. I never had my XR650R come close to 300F on single track or when in the dunes during the summer when I was datalogging oil temps a year or two ago.

I've read some oil and water temp. articles that water temp. is aprox.40 degrees cooler than oil temps.

I had found this to be true with my race car,they were usally withen 10 degrees of the 40 de.seperation when things were runnin normal.

Hope this helps with using the oil temp.dipstick :thumbsup:

I've yet to have my bike lose coolant,ha maybe i don't run it hard enough???

You can also buy reversible temperature labels that stick on various engine parts (i.e. frame, clutch cover, radiator, etc) if you want an inexpensive way of monitoring temps from places like McMaster Carr

Thanks for the information! I am going to get the temp oil dipstick and then go from there.

Thanks :thumbsup:

Thanks for the information! I am going to get the temp oil dipstick and then go from there.

Thanks :thumbsup:

Don't waste your money on the XROnly oil temp guage dip stick. They are prone to get water inside the guage window which makes it very hard to read and eventually just quits functioning. Mine lasted less than a year. The bike never overheats anyway once the power up kit is installed and you learn not to slip the clutch.

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