Is the stock radiator cap rated 1.4 BAR ?

[oddturkout]

Just bought a high pressure radiator cap to put on my rc390 cup bike without checking what it came with, turns out it's 1.4 BAR. Does anyone know if this is stock or cup only?
Thanks!

 

[Diploman]

The stock radiator cap is 1.4 bar. The upgrade cap sold by MNNTHBX is 1.6 bar. Quite a number of 390 owners have upgraded to the better cap with good results and no problems. An increase in pressure of .2 bar does not stress the system unduly, and raises the boiling point usefully. No coolant puking.

 

[Fasteddy]

Noticeably shorter fan cycles sitting in traffic and never gets to the last two bars with the 1.6 bar cap. An excellent investment!

 

[stevieboy]

Agreed. Fortunately (sarcasm) the second fan on my bike is loud enough to hear and it does seem to cycle better with the MNNTHBX cap.

 

[oddturkout]

Thanks for the info. KTM High pressure cap I got is 1.4 Bar. Will return and get the 1.6. Saw a heat warning when I came off the track and now reading all the head gasket issues, I am trying to keep this thing cool.

 

[rippedcb]

would 1.8 bar be too much?

 

[Fasteddy]

would 1.8 bar be too much?

It's only 2.9 PSI, check out comments in 1st page of this thread.

http://www.rc390-forum.com/forum/mnnthbx/1356-1-6-bar-quality-rad-caps-2.html