Radiator cap question

9 replies to this topic
  • Eagle426

Posted September 01, 2003 - 04:41 PM


Does anyone know off hand what year and model kawasaki radiator cap will fit the WR426? I read on here that some of the KX caps were a 1.3 psi cap, whereas the stock is a 1.1. It is supposed to drastically reduce the overheating/boiling over problem at really slow speeds. However, the post gave no specific details! Thanks!

  • Butta

Posted September 01, 2003 - 05:26 PM


Acutally, the KX cap is a 1.6. I got mine from a '99 or '00 I believe. Works great....I think they are ALL the same size caps, just different pressures.

  • Hick

Posted September 01, 2003 - 06:48 PM


Acutally, the KX cap is a 1.6. I got mine from a '99 or '00 I believe. Works great....I think they are ALL the same size caps, just different pressures.

Yeah, every motorcycle cap I've ever seen is the same, they are all interchangeable as far as I know. Also, every KX cap I've seen is a 1.3, though "every KX" is limited to a '95, '94, '98 KX 250 and '92, '99 KX 500.

1.6 seems a bit much, that works out to like 24 psi, vs. about 16 for the stock 1.1 cap, and about 19 for a 1.3.

  • Butta

Posted September 02, 2003 - 05:23 AM


I've had zero problems with the 1.6, even with a little "customizing" work I managed to do on the left radiator on a rocky trail in Colorado.... :)


Posted September 02, 2003 - 05:41 AM


Do yourself a favor and take your cap down to the local parts store and match it up with a 16 lb auto radiator cap. It will not cause any harm to your radiators, but will significantly increase the boiling point to where you will not be having the overheating problems.

I have been running 16 lb caps on all my bikes for years with no problems.

Bonzai :)

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Posted September 02, 2003 - 06:37 AM


Kaze, do you have a brand/part # handy?

  • ToSlow2Care

Posted September 02, 2003 - 06:44 AM


Yeah, KAZE if you could let up know what cap you are running we'd appriciate it. :)

  • Hick

Posted September 02, 2003 - 08:49 AM


Kaze, unless my math is wrong the stock cap is about 16 psi.

  • Wrench

Posted September 02, 2003 - 11:07 AM


the Kawasaki part #s are 49085-1070 for the 1.1 bar(15.9542psi)

49085-1073 for the 1.6bar (23.2060psi)

they don't list a 1.3bar on the 2001 kx250

All our jap bikes run the 1.6bar with no problems it's the first thing we change when we put guards on.


Posted September 02, 2003 - 11:59 AM


All three of my stock caps in my tool box tested out between 12 and 14 lbs.

The cap on my 426 tests out to 17.1 lbs even though it is clearly marked 16 lbs.

I have caps from three different manufacturers carried by auto-zone, all seem to be doing the job just fine.

Bonzai :)


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