Coolant not circulating in my 04 FZ6s

[Alexander5025]

I recently bought a used bike - 2004 Yamaha FZ6s; 11,000 miles, starts every time and mechanically sound except it tends to overheat and after changing out old, nasty, brown coolant I poured in new green stuff. I notice the old coolant, as well as the new coolant is not circulating within the engine based on squeezing the radiator hoses. Has anybody had a same issue?
What happened? How do I resolve non-circulating coolant issue and overheating when I'm at a traffic light?
Is this just a case of doing a thorough coolant flush? Or is it my thermostat? Or water pump parts need replaced? Is it an issue with impeller? Please help. This really worries me a lot.

 

[TownsendsFJR1300]

I seriously doubt you have no circulation.

What temps is it getting up to?

Can you check and see that the fan spins freely? Its not uncommon for a rock to jamb it up and burn out the fan motor.

If you start the bike cold and let it warm up, you should eventually see coolant flowing with the radiator cap off.

You could possibly have a bad thermostat but its somewhat rare. Check the basics up above first...

 

[Alexander5025]

I seriously doubt you have no circulation.

What temps is it getting up to?

Can you check and see that the fan spins freely? Its not uncommon for a rock to jamb it up and burn out the fan motor.

If you start the bike cold and let it warm up, you should eventually see coolant flowing with the radiator cap off.

You could possibly have a bad thermostat but its somewhat rare. Check the basics up above first...

The fan spins freely once the bike reaches the high threshold temperature. Even then, the radiator hoses both outflow and inflow are limp. Just nothing going through them. This is like having a heated kettle strapped on the front of the bike: the water boils after a while but as long as you're moving, the wind cools it down. Although the fan spins, the temp still rises. I have to literally air-cool the bike while on the move. Sorry for the 19th century analogy.
I looked through all the threads on FZ6 forum and nobody has mentioned "coolant not circulating" despite overheating issues and changing out brown coolant issues that were mentioned.
I'm a new rider but I've been forced to learn quick about bikes because only two wheels hold my life in tact.
I really hope it's a thermostat issue because I hear there only $30 + 1 hour of labor at the shop, but I just wish somebody had at some point experienced this before or successfully fixed a similar issue.

 

[TownsendsFJR1300]

Its really odd that your not getting any movement of coolant.

The only thing that pumps the coolant is the impellor, part of the water pump on the right side of the engine. Even if the thermostat was stuck closed, you should still see some movement there.

Here's the parts fisch for your water pump; Yamaha Motorcycle Parts 2004 FZ6 - FZ600SS WATER PUMP Diagram

Its fairly simple.

Quick question, did you run the ENGINE AT ALL WITH NO COOLANT? That alone will quickly damage the pump.

Just to verify, you may be able to look down where the main hose goes to the water pump and slowly crank the engine. You want to look and make sure the impeller IS INDEED TURNING.

I'll send you a PM that should help...

 

[Serzedo]

Maybe water pump.

Does the liquid mantains the level? Or does it get lower? It might be consuming water.

Or could it be a broken thermostat? That is always in a closed position and water doesn't circulate.

"V"

 

[Motogiro]

If the hoses are soft and squeezable with no resistance you may have a bad radiator cap. The cooling system is a closed system meaning it uses a recovery tank for overflow. As the bike cools it sucks coolant back into the radiator from the overflow storage tank. This eliminates air from the cooling system making it more efficient. Check the small hose that goes from the radiator neck to the recovery tank.

Also your coolant should be a 50/50 mix of water and coolant. Most coolant you buy today is already 50/50 so you don't need to mix it.

Here's a video on the basics of a radiator cap. https://www.youtube.com/watch?v=0JdDWWoX-70

 

[Alexander5025]

Maybe water pump.

Does the liquid mantains the level? Or does it get lower? It might be consuming water.

Or could it be a broken thermostat? That is always in a closed position and water doesn't circulate.

"V"

The coolant liquid is at the same level all the time. I hope it's a broken thermostat that's always in the closed position instead of something more sinister like changing out entire water pump or radiator (yesterday a Yamaha dealership hypothetically quoted me $600 for radiator alone IF it needed to be changed out plus labor costs which could cost me total over $3,000). I wonder how much it would be to fix it if it's only thermostat issue. I'm leery of mechanics now; they may create problems out of thin air and tell me that all parts of my cooling system need to be changed out and I'll have to pay $120 per hour for their labor in addition to thousands of dollars for parts.
I really just want an honest mechanic to give an honest assessment.
Looking at online reviews of local repair shops through the Yelp App I'm horrified how shops to include the Yamaha dealership of course take advantage of customer demand because everyone is stuck in Hawaii and can't get to the mainland to fix their bikes. Business competition naturally produces better customer service and honest work to attract more customers. Here I feel there is no competition and never-ending demand for service because of the year-round riding Hawaii climate;. So it's just one huge loosely organized mafia running the show for bike repairs.

 

[TownsendsFJR1300]

the entire system is pretty easy, especially if your somewhat mechanically inclined. IE, you can swap that radiator out in easily 30 minutes yourself if need be.

Does you fan kick ON when the engine gets hot, say sitting in traffic?

 

[Alexander5025]

the entire system is pretty easy, especially if your somewhat mechanically inclined. IE, you can swap that radiator out in easily 30 minutes yourself if need be.

Does you fan kick ON when the engine gets hot, say sitting in traffic?

Fan does kick on and seems to be working fine when sitting on one spot without moving, but it's insufficient to cool down the engine in hot weather.

 

[TownsendsFJR1300]

Ok, good. As Motogiro mentioned above, the radiator cap is more likely your issue. If it won't hold pressure it'll over heat.

If the thermostat stayed closed, it would flat out overheat ALL THE TIME, no matter what.

You may be able to get it checked but a new one is cheap enough and very simple to install...

Its pretty rare for the thermostat to fail in these engines..


The more info you can provide, the easier it is for us, especially over the net, to diagnose

 

[Alexander5025]

Thanks for the video on radiator cap; I never thought its functionality was that complex. This is good to know. I may just buy a new one if its the actual problem but the radiator cap seemed fine. I unscrewed the screw that kept the cap in place and twisted it off. It seemed there was a tight seal but what do I know...
I may just buy a brand new one just to see (and hope) that's the main issue.
I just inherited this bike and there were two owners before me so I don't know what they did. They might have never changed the coolant out in their lives but when I changed it, the old coolant was brown and nasty - not exactly watery as it should be but definitely not mixed with oil because it would have risen to surface in my draining pan.
I feel like the coolant is clogged up somewhere along the way.
I still have to undo the radiator hose that's leading down to water pump and quickly start the bike to see if impeller is spinning. My bike is currently Travelling with my household goods and should be here soon.
I miss riding.

 

[Motogiro]

Another thought. I once worked on a Dayton 675 that was overheating. What had happen was the someone somehow soaked the radiator with motor oil. That oils stayed in between the radiator cooling fins and as the owner rode it the over heating problem increased as the oil capture dirt in the air and eventually completely blocked any air flow. I soaked the radiator with S-100 cleaner and flushed the radiator fins from the back of the radiator and an amazing amount of crap was cleared out of the fins. Bike ran really cool after that.

 

[iSteve]

Before you spend money on this what do you mean by overheating. Is it like 220F degrees hot or like 260 hot. You say it cools down from air, this would indicate that the system is working fine but the fan isn't.

 

[FinalImpact]

It sounds like its pushing coolant out as the main issue. Just like Cliff said, the cap is a key part to system. If it cant hold a vacuum it wont fill itself. If not full and it gets hot, it boils over. The cap is the weak link here.

Clean or replace the cap and check the INNER seal that is deeper into the radiator. If it does not seal, the system will fail. A tiny flake of debris under that seal can compromise the whole system. It relies on the cooling cycle to purge the system of air. i.e. each time the engine cools down, the fluid contracts. This action makes a vacuum which pulls in fluid from the reservoir. Any leak in the system Either under pressure or vacuum will compromise the all weather functionality.

Also, check the coolant tank that the overflow hose is 100% intact and reaches near the bottom of the reservoir and that the reservoir has coolant.

You can unbolt the radiator and nearly do a 100% visual on it for internal plugging. But an IR temperature sensor will tell you a lot too. Cold spots would indicate no flow.

This spring loaded valve and seal must function and not leak.

 

[TownsendsFJR1300]

Unless you have a hose leaking badly, as Cliff mentioned, the cap is about the only thing preventing ALL the hoses from pressurizing / getting hard.

Even if the radiator was clogged, the hoses should still firm up once at temp...



BTW, it doesn't hurt to snug up ALL the coolant hose clamps once in awhile. They do tend to loosen up with the numerous heat cycles.

 

[TownsendsFJR1300]

Any updates???


PM sent to OP..