Safe operating temperatures

[0101]

What is generally considered a safe operating temperature for our 400EX's?

After a long hard ride in the desert today (75* temps), my infared thermometer gun registered 260* F when I pointed it at my head/cylinder. Seemed a little high to me, but is this normal for these air cooled bikes?

11:1 416 w/stage 2 hotcam running on 91 octane.

with the same mods i've had my oil temp(using an al bakers therm dipstick)at 275-290 300 before installing spal fan and FST auxiliary oil cooler.TT vapor read around 240-260 at the top of valve cover where they mount the sensor.fan took me to around 250 oil temp(210-240 on TT).still felt high to me so i added the cooler and ran around 2-210 oil temp with um air scoops(170-200 with TT).that was with ambient air temp around 75-85.in 35 or less ambient air my TT vapor ceased to register a temp at the top of the valve cover(meaning oil was apparently less than 100).my therm dipstick crapped out this winter so i had no comparison there.

your readings seem accurate considering different methods of measure,that being said i personally felt it was too much.

[powerbomb400]

But its a air cooled engine and that the beauty of them. I agree the cooler you can keep them better off you are but at least you don't have to worry about boiling the water and antifreeze.

[crownandmonster]

250* oil temp is about the high limit. The reason being when oil gets that hot it starts to break down and lose its ability to lubricate. If you are just using a laser gun and pointing it at the head and getting 260* then you should be fine as your oil will be cooler than that.

[Crosshairs]

Originally posted by crownandmonster
250* oil temp is about the high limit. The reason being when oil gets that hot it starts to break down and lose its ability to lubricate. If you are just using a laser gun and pointing it at the head and getting 260* then you should be fine as your oil will be cooler than that.


Conventional oil may be good to only 275-300 but synthetic is good to over 400....not that you ever want to see your oil that hot, but it will not break down like conventional oil will .
knowing how hot these engines can get, I only run synthetic in mine

[chevymanrick]

Originally posted by Crosshairs
Conventional oil may be good to only 275-300 but synthetic is good to over 400....not that you ever want to see your oil that hot, but it will not break down like conventional oil will .
knowing how hot these engines can get, I only run synthetic in mine
X2 I only run synthetic in mine to and its fairly stock I just like having that little extra insurance

hows the synthetic working on the wet clutch setup?you guys seeing any slip?

powerbomb400 tstudy this.......

http://www.exriders.com/vbb/showthread.php?s=&threadid=485240

[chevymanrick]

Originally posted by PAxcThumper
hows the synthetic working on the wet clutch setup?you guys seeing any slip?

powerbomb400 tstudy this.......

http://www.exriders.com/vbb/showthread.php?s=&threadid=485240
My clutch hasn't slipped once, have people had that problem while running synthetic?

[dxcody]

Originally posted by chevymanrick
My clutch hasn't slipped once, have people had that problem while running synthetic?

I havent really heard any complaints about synthetic on 400ex's.

Had a few friends say that synthetic isnt good in 450R's.

[powerbomb400]

That was real informative PAxcThumper. Safe operating temp to conventional oil to synthetic oil good example.

[Crosshairs]

Originally posted by PAxcThumper
[B]hows the synthetic working on the wet clutch setup?you guys seeing any slip?



I use Amsoil an they make a motorcycle specific oil that is safe for wet clutches...

Just make sure whichever synthetic you buy is wet clutch safe and you wont have any problems.

[chevymanrick]

Originally posted by Crosshairs
I use Amsoil an they make a motorcycle specific oil that is safe for wet clutches...

Just make sure whichever synthetic you buy is wet clutch safe and you wont have any problems.
I use Honda synthetic oil it works great

[JOHNDOE83]

OMG seriously 260 degrees:huh

My 440 barely gets 200 degrees without any cooling mods runs mostly 190ish:eek2: