Oceans05

Hey guys

Have had some problems with my 636... leading to head aches... I have tried searching extensively here and online for possible issues... all lead to faulty thermostat..

I've had the bike for about 4 years now, and never had too many problems with over heating.. About two years ago I was planning to take my bike to the track, and swapped out my stock anti-freeze with water + water wetter, now the temps with the anti freeze hovered around 190-200 ish... after the water wetter, they were about 200-212, a smidge hotter but not too bad, always kept itself in check after I started riding.

I had a job in the florida keys for a year and did not ride my bike too much all last year, maybe once every few months, when I came back recently, the bike over heated to 240.. and would never cool down below 212

I flushed the system again with water and water wetter, and the problem still existed, I linked it to a faulty thermostat. I did the maintenance my self and the thermostat seemed fine but replaced it anyway (i had already ordered it ) amid my repair, I broke the thermostat housing

so I finally got the new housing and put it all back together and used engine ice this time, and all seemed well, would goto 212, but fan kicked on and it cooled back down to 200 for the around-town test rides


I went for a ride this weekend to the everglades (45 miles one way) and almost to my destination the bike eventually crept up to 240 again (i was riding ~90mph about 30 miles)

I stopped for gas and let the engine cool in the shade, then i went back home (another 45 miles into head wind) and the damn bike didnt go above ~204.

I was riding in ~88 degree weather, the reason why I think the bike stayed cool on the way back was because of head wind? and as I approached the city the temps which were noticeable cooler than in the everglades...

I have bled the system and followed the user manual on how to properly fill up the coolant, I am going crazy because the bike is still over heating after spending about 120$ trying to fix, I was debating whether or not to remove the thermostat completely but since I put a new one in there it should be functioning fine.. the fan kicks on at 212 as it should,

could it be a faulty sensor? what am I doing wrong? I thought for sure the Engine-Ice would be better than the water-wetter but it seems to be functioning the same...

Sorry for the book, but thought the more descriptive I was the better I'd be able to get an answer... Thanks!!

1poorvw

Does that bike have a radiator cap? I went through all the same issues as you and a 10 cap from napa did the trick.


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awiner

Does your fan kick come on at approx 205 F ?

Have you bled the air from the system?

__________________
2005 Kawasaki ZX-6R
2005 MV Agusta F4-1000S

Oceans05

yes there is a radiator cap and the seal doesnt appear to be broken, there are no apparant leaks from the cap

and yes the fan comes on at 212, and yes I have tried to bleed the air as best as I could, I ran the bike with the cap off and slowly gave a little throttle to let the bubbles out, I slightly hit the radiator hoses to knock any loose bubbles..

I put the cap back on and ran it to 212, then turned bike off to cool down a bit and then opened cap and slightly topped off the coolant to the tip top of the opening

1poorvw

It's not just about the seal and the bubbles. As coolant....especially water....heats up it expands, increasing the pressure inside the cooling system. Under that rubber seal is a spring that will vent that pressure at a certain temperature. That spring and the seal are prone to failure. As a liquids pressure increases the boiling point goes down, so if the cap isn't functioning properly and venting the extra pressure it will over heat.

Take it or leave it, you've already dumped a shit ton into this issue......what's another 10 bucks and a possible win?


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Oceans05

Hmm.. Good explanation, thank you

I did not understand thats how a radiator cap functioned, is there a way to check that it may be a bust, or is it a gamble on another part?

awiner

There is a procedure to check the proper operation of the radiator cap using a pressure tester if you have access to one.

Radiator Cap Inspection
•Remove:
Right Upper Inner Fairing (see Upper Inner Fairing Removal in the Frame chapter)
Radiator Cap

•Check the condition of the bottom and top valve seals and valve spring.
If any one of them shows visible damage, replace the cap with a new one.

•Install the cap on a cooling system pressure tester.
NOTE

○Wet the cap sealing surfaces with water or coolant to prevent pressure leaks.

•Watching the pressure gauge, pump the pressure tester to build up the pressure until the relief valve opens: the gauge needle flicks downward. Stop pumping and measure leak time at once. The relief valve must open within the specified range in the table below and the gauge hand must remain within the same range at least 6 seconds.

Radiator Cap Relief Pressure
Standard: 93 ∼ 123 kPa (0.95 ∼ 1.25 kgf/cm², 14 ∼ 18 psi)

If the cap can not hold the specified pressure or if it holds too much pressure, replace it with a new one.

__________________
2005 Kawasaki ZX-6R
2005 MV Agusta F4-1000S

1poorvw

You may be able to bring it to autozone/NAPA and they may be able to test it for you as well.


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hotzx-6r

not worth testing and 'maybe' its probably OK
...just change it ..as stated above: it aint exactly expensive

Oceans05

thanks guys for the help..

i found this website and it helped explain things considerably... Overheating: Symptoms and causes

one more question, is there a specific radiator cap that is needed? a certain PSI rating? size? can I pick it up at autozone or should I order it directly from kawasaki?