optimal bike running temperature?

[coryf89]

Ive got a 2013 ktm 450 with a thumper racing 520 big bore. 2017 yeti 129. no engine jacket and I forgot the skid plate today. it does have a thermobob, a pr2 tuner, PC ti-2 exhaust.


the trailtech voyageur which is plumbed into the thermobob said 70-80C (160-170F) all day. this was a break in ride on a new top end so I didnt go hard at all, lots of stopping (rmk spark plug issue), the snow sucked, no fresh powder, and it was very warm so the snow was sticky and wet. it was like +5C (40F) today. I rode for 1 engine hour.



is that temp range concerning? ive been outta the snowbike world for over a year now so not too sure what the optimal temps should be, why they should be that, and cant remember what my normal temps are on cold, deep powder days. if theyre too low, the bike runs in "warm up" mode and dumps extra fuel is the concern? even with the pr2 tuner?



ive never had an engine jacket, usually just the plastic acerbis skid plate which doesnt do anything TBH. does the engine jacket really make a night and day difference?


ive sent it in for an oil analysis a while ago and my fuel dilution wasnt concerning, despite some cold days and no engine jacket. I do change oil every ride which is one oversized tank of fuel.


thanks.

 

[2smokin]

if 160 to 170 doesn't have you cold looping its not the end of the world, 190 or so would be better though. radiator blocking could also be an option but would be a pain on the trail.

 

[Revv Up]

In an ideal world 190- 200 f is the temp the bike was designed to run at but with our constant change of elevation, snow depth and snow pack it’s hard to hold right at that temp.

I’m surprised your running so warm without something shielding the snow off the motor.

 

[byeatts]

In an ideal world 190- 200 f is the temp the bike was designed to run at but with our constant change of elevation, snow depth and snow pack it’s hard to hold right at that temp.

I’m surprised your running so warm without something shielding the snow off the motor.

Yeti and camso run much hotter, The snow doesnt pelt the backside of the motor sucking temps down.Thats how sleds cool from heat a exchanger located where bike motor is.also the ECU fueling lean vs rich can give a 20 degree difference

 

[coryf89]

200f is 93C, good to know. seems a tad warm. even cruising in the summer and getting lots of airflow on fast double track it wont even hang around the 95-100C mark. usually the same. 70C if youre riding quick so thats interesting. I got two bikes with two temp gauges each + a rad cap temp gauge that matches the digital TT ones that I watch religiously.


the reason I ran so warm the other day is because it was a very warm 40F/5C out and literally zero powder spraying up at the motor.


whats the problem with running a tad cool? is it the "warm up" mode feature and dumping extra fuel which washes passed the rings and dilutes the oil? I thought the pr2 disabled that and kept the fueling consistent?



I am going to run a full tank, with no engine shield, and monitor the temps, then send the oil in for an analysis which will show me the fuel in the oil, among other things just to see.