High/Erratic Coolant Temp 270SM tuned sled

[DMCTurbo]

Does under pressure mean just warm, or running?

Start your sled and let it idle until the thermostat opens (75c), you can feel your rear heat exchanger get hot once the thermostat opens, then while still running crack that screw and bleed the air out. You may have to do it a few times. Let the sled cool and repeat.

 

[jonlafon1]

The bolt/ plug has a rubber o ring on it that needs to be checked and replaced when worn. Don’t over torque this bolt and o ring . Snug it up good. That’s it.

 

[VyperNation]

The bolt/ plug has a rubber o ring on it that needs to be checked and replaced when worn. Don’t over torque this bolt and o ring . Snug it up good. That’s it.

Thank you for that tidbit, I will get one on order just to have.

This morning’s update is that it definitely burped some air on this first bleed. Cooling down now for another round. Remaining cautiously optimistic this is indeed the issue.

 

[Confused]

I was plagued with over heat issues last year when I bought my SW. I installed scratchers and at the same time added Amsoil's coolant treatment and bled the air. I have yet to use the scratchers since. The coolant treatment may have helped some but bleeding it was the ticket. I rode last Saturday on EXTREMELY thin trails and never seen over 172.

Below is normal operation from cold start to warmed up all at an idle.

-start sled cold
-watch the coolant temp slowly climb (several min)
-once it hits ~168, the tstat opens and the temp drops to <160
-left coolant runner in the tunnel gets warm and the rear exchanger starts to get warm
-temp slowly climbs back to 168 and drops again to a little over 160
-rear exchanger is now warm and the right runner is starting to get warm.
-temp climbs again to 168 and drops 3-4 degrees
-temp climbs again to 168 and drops 1-2
-temp climbs again to 168 and stays
-if I let it continue to idle, it will climb >170, sled is fully warmed up

edit - I'm super anal about warmups. My friend hate it lol. Probably not as critical on 4 strokes but something I carried over from my 2 stroke days.

 

[FrozenTows4]

Nothing wrong, but everything Right, about letting them totally warm up.
Makes me cringe watching my friends want to roll with 60 degree 2 stroke coolant temperature.
They either wait or I catch up later.
No dishonor in proper warm up.

 

[VyperNation]

Post rip update: Problem fixed!!!!! I bled it twice this morning and everything has settled back down.

Also, thanks again for the heads up on the O-ring. Dont assume because its basically a new sled that its ok… Pulled the plug to check it and it was trashed. After a momentary meltdown, I discovered that its the same o-ring as the oil tank drain plug, which I keep on hand as I replace it every time I pull it. Crisis averted!!!!

 

[Turboflash]

Post rip update: Problem fixed!!!!! I bled it twice this morning and everything has settled back down.

Also, thanks again for the heads up on the O-ring. Dont assume because its basically a new sled that its ok… Pulled the plug to check it and it was trashed. After a momentary meltdown, I discovered that its the same o-ring as the oil tank drain plug, which I keep on hand as I replace it every time I pull it. Crisis averted!!!!

As we all find out, properly bleeding these 998s is CRITICAL. They are very fussy about that. Lots of threads on TY about this.