2001 yzf426 Overheating problems

I have a 2001 YZF426 with the JD jet Kit, White Brothers exhaust, 13 0z flywheel, and everything else is pretty much stock. Once a year myself and 10 guys go on a riding trip up to the Kern River near Lake Isabella and I overheat every year. Last year I geared the bike down and it was worse than before. I ride local trails the rest of the year and never have a problem. I was told to put a Kawasaki radiator cap part # 49085-1059 and it would make a big difference. The stock cap is a 1.1 and the new cap is 1.6.

Does anyone know if this will help or is it a waste of $50.00?

Thanks

I was told to put a Kawasaki radiator cap part # 49085-1059 and it would make a big difference. The stock cap is a 1.1 and the new cap is 1.6.

I had the same problem with my 01 YZ426. I started using engine ice and for the most part solved my problems. IMO going to a 1.6 cap may case damage to water pump and or seals. Spend the money on a recovery tank. Here is one form MotionPro or make your own.

I had the same problem with my 01 YZ426. I started using engine ice and for the most part solved my problems. IMO going to a 1.6 cap may case damage to water pump and or seals. Spend the money on a recovery tank. Here is one form MotionPro or make your own.
Engine Ice works well, as do a couple of the Evans coolants. EI is basically just propylene glycol coolant premixed with water, so it's a little over priced in that sense, but it is convenient and it does stay in the radiators better. Your current coolant may just be old and tired, too. It happens.

On the cap, have your original 1.1 tested to see if it actually holds that pressure. TDLF, you know? The caps are marked in bars. One Bar equals normal average atmospheric pressure at sea level, or 14.7 psi. A 1.1 bar cap should hold 16.1 pounds. 1.6 bars is 23.5 psi, which is considerably higher, and in order to withstand that, your entire cooling system would need to be in good condition. You do NOT want 270 degree coolant sprayed on your leg when a hose blows off.

If the coolant and the new cap don't do it, look into the recovery tank.

I have a 2001 YZF426 ... I overheat every year.

Just making sure: Do you fill the radiator to the top, or leave some air space, 'cause the coolant needs some room to expand? Filled to 10mm above the core is normal.

I fill my radiator to the top and it usually will puke a little out if I sit in one spot too long

but never more than a few drops or so but I keep moving and if I stop I just shut it down

I have a 2001 YZF426 with the JD jet Kit, White Brothers exhaust, 13 0z flywheel, and everything else is pretty much stock. Once a year myself and 10 guys go on a riding trip up to the Kern River near Lake Isabella and I overheat every year. Last year I geared the bike down and it was worse than before. I ride local trails the rest of the year and never have a problem. I was told to put a Kawasaki radiator cap part # 49085-1059 and it would make a big difference. The stock cap is a 1.1 and the new cap is 1.6.

Does anyone know if this will help or is it a waste of $50.00?

Thanks

Lets look at the real problem. Its fine all year long, but when you and your 10 buddy's go ride then it boils over. I would say you need to find some faster friends to ride with, that way you can get some air thru the radiators. :thumbsup:

If your cap tests fine then consider the Boyesen water pump cover/impeller. I've seen improvements while using it on a WR450 and I would expect similiar results on a YZF.

Thanks for all your help, I will definately try the Engine Ice. And yes I do fill my raditator to the top. I might even try the cap if I can find one.

Thanks

And yes I do fill my raditator to the top.

That's why it's spewing out then.

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