Operating Temp for XR650L?

Anybody know the redline for operating temp on a XR650L? I've hit 300 a few times, and it really concerns me, me not knowing any better. If anybody could clue me in as to the normal operating temp range, I'd really appreciate it. :)

Eng. oil at 300 deg.? Wow...I'm not sure whats normal for your bike, but after years of car racing, 300 deg. is HOT!

At one time I was going to install a gauge on my bike(replace the factory dipstick) but then I decided I didn't want to know.. :)

I've got the temp gauge dipstick that Loufish is talking about and I've never seen mine over 250.

Are you jetted too lean?

300 degrees is too freaking hot. my 650r runs under 200 mostly, hottest it's been is 210, in 1st gear stuff. put an oil cooler on, rejet.

I don't know specifics but this is what I'm thinking and my rationality may be off but I'll keep checking to see what others say. anyway here goes.

a) Engine oil temp is a reliable measure of Engine Temp if its measured before a cooler if applicable.

:) Water temp is also a reliable measure of engine temp, (thats what other engines measure for engine temp)

c) coolant thermostats open at a specified temp to keep engine temps in the range of the thermostat (not sure what the XR650R is but cars can run 155-225 degree thermostats comfortably b/c oil breaks down or breaks down faster at higher temps)

d) I assume air cooled engines should operate functionaly around same temps b/c they run on the same motor oil that would begin breaking down at the same higher temps?

I know this doesn't give you a direct answer but it seems that it should be well below 300. This chain of thought is just a guess w/out me researching anything. I am curious as to what others are running actually and how it compares to the thermostat temp?

Thanks for letting me post my theory


I don't know about the air cooled 650L, but my 650R coolant temp. runs between 190-210 depending on the ambient air temp/riding speed/and jetting that I'm running. I've never seen it hit higher than 210. Also I think my thermostat is stuck open now, for some reason. Anyway.

Air cooled engines run hotter, naturally, and is the reason that that air cooled engines have looser tolerances, that is the engines parts have more play in between them to lower the friction and thereby the heat. But they still run hotter anyway. A reason they don't last as long either.

However, 300 degree oil temp is too high no matter how you look at it. It's quite obvious that your jetting is too lean, the oil level is too low, or the bike is being ridden at walking speed in 100 degree heat for extended periods.

Jet the bike richer on the main, and raise the needle clip a couple of notches and see how it does. Good luck with it, and I'm sorry I'm not more familiar with the XR-L .


Thanks for the advice. I just rebuilt the entire bike, so, rejetting doesn't sound too farfetched. I'm running an Edelbrock Pumper, so it shouldn't be too much of a pain to adjust. Thanks for the info.

How will I know when it's just right, and not too rich? :)

LOL, yes, I know, how can I rebuild a bike and not know? Sorry, carburation has always been somewhat of a mystery to me. :D

Thanks for all the help, ya'll. Keep the comments coming.

Yo Billyboy

I have the same problem with mine.It's probably a jetting issue.I put a pipe on my oh3 @300 miles.Also a uni filter,then i bought a temp gauge.Before i rejetted i was running @275 just cruising .It would climb from there if i got on it(i never let it get to 300)Im still messing with the jetting.I've tried all kinds of combos(stock air filter,Q-core for the pipe,dyno-jet kit ,pilots up to 58,mains up to 170.I did get oil temp down to 240 (no load)280 on it.I think thats the best it's gonna get.SRC racing &xr's only both say normal temp. is 250-300.But dont let it get over 300,thats when the oil starts to break down(i'm changing mine every 200 miles)Good luck and enjoy your XBRP(xtra big red pig) :)

If you want a solution, put an oil cooler on that pig. Trust me, you don't want to go out into the desert and overheat... Oil coolers are cheap and they work. I've had lot's of air cooled thumpers and oil coolers work awesome. Hell, they work so good, I sometimes wonder why we have water cooled desert bikes anyway. I worry about getting a leak in the middle of the Mojave, Devils Playground sometimes, you know... heh. I'd hate to be the guy buying your bike after you've ran it at 300 degrees all day too... that's why I never buy used. Oh and take that smog crap off too! :)

I talked to Rob Barnum, and he says it's way too hot, but, he's not sure how accurate the temp gauge I've got is. We talked for a while, and he suggested several things I'm going to try.

As for uncorking? Long time done.

Oil cooler? I'd love to. Where can I get one for my bike?

Someone please tell us the location of the elusive (sp?) oil cooler, sounds like a great idea to me!


did a quick search in metacrawler, found a lot of info. "You may also be able to adapt a XR250/XR400 oil cooler to your bike with a little bit of work and that should further help with oil temps while moving at speed." "The only thing I've seen is the weld on fins from Thumper racing." Try http://www.jagg.com/ they sell coolers. also, I did a search in TT forums for cooler and fins, found this (among many other referneces): "For the money, the oil cooler would be a better way to go in my opinion. Get one from a XR250 or 400 and mount it. You can buy a kit from SRC and other places also. Also run good quality oils such as synthetics in the motor.

For increasing the cooling to the motor, trim the rear of the front fender about 2" to increase the amount of air to the cooling fins. Works great except when muddy"

There's a good article on mounting a fan, but that looks like a lot of work. Good luck! :)

here's a dope fly cooler for ya (and a dope fly price to match): XR-600/650L Oil Cooler Kit

Item #: 1661

Our Price: $356.40

SRC Summers Racing Components has released an oil cooler kit for the Honda XR-600/650L that uses the efficient XR-400 oil cooler as the heat exchanger. SRC fabricates a bolt-on mounting bracket and braided stainless steel oil lines. The cooler mounts to the steering head behind the headlight assembly. The cooler keeps oil well below the critical 300ºF temperature..

Looks like they upgraded their site too.



I run  pretty consistent 200 degrees in summer. Lil less in winter.  20-50W oil.  if I run 10-40W it goes up a tad.  Uncorked. FMF Q4, and 6,100 miles on a 2005 XR650L.  I did creep way up towards 300 sitting in traffic....one time.  Got off onto side roads and it cooled right down.

Edited by Motosprtman

Sutton oil cooler kit out of phoenix,az,high quality kit with all brkt's hardware for about 300 bucks, check on advr rider website for link.

flat out mine was 136c and very slowly climbing but

i have 10w50 semi-synthetic which has a flash point of 226c (full synth is 236c)


motul oil


5100: semi synth

Color Visual Amber
Viscosity grade SAE J 300 10W-40
Density at 20°C (68°F) ASTM D1298 0.871
Viscosity at 40°C (104°F) ASTM D445 89.8 mm²/s
Viscosity at 100°C (212°F) ASTM D445 13.82 mm²/s
Viscosity Index ASTM D2270 157
Pour point ASTM D97 -33°C / -27°F
Flash point ASTM D92 226°C / 438.8°F
TBN ASTM D2896 7.5 mg KOH/g


7100: full synth

Color Visual Red

Viscosity grade SAE J 300 10W-40
Density at 20°C (68°F) ASTM D1298 0.859
Viscosity at 40°C (104°F) ASTM D445 88.8 mm²/s
Viscosity at 100°C (212°F) ASTM D445 13.5 mm²/s
Viscosity Index ASTM D2270 154
Pour point ASTM D97 -33°C / -27.4°F
Flash point ASTM D92 236°C / 456.8°F
TBN ASTM D 2896 8.4 mg KOH/g


mineral oil was like a scary 140c

Edited by redNwhite

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