401 at .040 are know to run hotter or warmer. You have EFI, so your mix is set right. You could try to run a bit richer... some of the old air cool Off Road bikes run hotter... and usually a tad richer does the trick. I have a oil temp gauge on the XR and I know that a steep uphill climb will gets the engine (NOT the OIL) in the 270ish after 30mins... so I stop and enjoy the views. When I tried to play with richness, it did not do anything...
I would check the oil temp with a infra red thermometer otherwise known are non-contact thermometer, the oil will be 10 to 30 degrees hotter.
The easiest could be to run some of the fancy cooling liquid to see if it helps, I have a bottle of water wetter, but never used it. We know that water cools better than coolant, play with the % coolant/water.
Removing the pintle that allows for air purge in the thermostat helps, or drill a small hole.
Otherwise 205 to 210 is not that terrible as long as the temp is staying in that range.
Edit after FSJ junkie post...
I have never really checked the exact temp when the temp gauge ran toward the 3/4... I keep driving, and a few minutes later the temp will go back below the middle and toward the 1/3... It all depends on the driving situation, long uphill, hot day... same hill different time of day, the OEM gauge will respond differently.
Add a trans temp gauge, that is a good indicator of what is happening overall... a few years back driving back from cold weather, 35F at high elevation, the trans oil never managed to go past 100F for 70miles until the outside temp was in the 50F...
74 wag, 349Kmiles on original ticker/trany, except for the rust. Will it make it to the next get together without a rebuilt? Status: needs a new body.
85 Gwag, 226 Kmiles. $250 FSJ test lab since 02, that refuses to give up but still leaks.
See Ouray 2013
, Engine bits
and Fuel and brake lines
, and Body work
Last edited by letank : 03-21-2021 at 08:10 PM.