Temps rise once bike is shut off, how to bleed the radiator?

[shreeshar7]

Hey all,So,here's the problem,
When I run the bike for 20+ kms at high rpms continuously lets say in the twisties.it runs all fine but once i turn off the key,and turn it back on, themp bar goes all the way upto 11-12 bars and shows high coolant temp,but once I start the bike and let it run for like 15 secs,the tempscome down to 10 and 9-8bars when ridden for a while. Temp usually stays at 8 bars while riding.
On two other rc390s that we took for test the temps would go maximum to 10 bars when shut off after some hard riding.

Could this be air in cooling system?
Whats the exact procedure to successfully remove any air bubbles.?

 

[Hunterbear]

Hi shreeshar7,

Check post#10 on this thread from the KTM Duke 390 forum: http://www.ktmduke390forum.com/forum/engine-technical-discussion/16873-engine-ice.html

The procedure of bleeding air out is simple, even if you're not switching to Engine Ice. I did and my temp never goes over 8 bars, even when ridden hard in the heat of Southern California.

You can also replace the radiator fan, here's another thread from that forum about it: http://www.ktmduke390forum.com/forum/ktm-duke-general-discussion/17241-spal-fan-instal-how.html

You can also replace the radiator cap, here's the link from this forum: http://www.rc390-forum.com/forum/mnnthbx/1356-1-6-bar-quality-rad-caps.html?highlight=radiator

Hope it helps!

 

[Ryanthegreat1]

Sounds like normal operation to me. You are seeing heat soak.

 

[shreeshar7]

Sounds like normal operation to me. You are seeing heat soak.

Heat soak is fine..but temps go almost to all bars.. Thid never used to happen before, on my friends bikes it doesn't rise over 2 bars due to heat soak.
Do something is wrong.

 

[Deleted member 452]

I had the same problem and the bike would puke coolant every ride but I think I found the problem (Haven't ridden in the summer yet). Either my radiator cap wasn't on all the way or there was air in the system because the 3rd time that I bled it, I noticed my radiator cap wasn't on all the way. There have been no bumps in temp when shut off and restarting or coolant loss in 1.5K miles.
*Running SPAL fan, Evans waterless coolant, and high pressure radiator cap.